Help & Guide

Everything below covers the app in depth. For quick answers to common questions, see the Support page instead — this guide is for when you want the full picture.

Video Tutorials

The whole app in short videos — 23 quick tutorials, most around a minute, from your first collage to a finished photobook. They're silent with on-screen labels, so they work fine muted. Watch the full series playlist, or jump to a topic below.

Getting Started

The whole workflow starts with two steps:

Load Photos — choose a folder. Every supported image inside it (including subfolders) is added to your library.
Generate — the app automatically distributes your photos across as many pages as needed, in a randomised mosaic-style layout.

Before you press Generate

A handful of settings in the sidebar shape what Generate actually produces — worth setting these deliberately rather than leaving them at their defaults:

Number of Pages — a target rather than a hard cap. Generate uses every photo in your library, distributing them across pages while keeping each page inside your Photos per Page range. It lands on exactly the number of pages you asked for whenever the arithmetic allows — that is, when your photo count falls between pages × minimum and pages × maximum. When it can't, it flexes the page count rather than dropping photos: more pages if you have too many for the target, fewer if you have too few. Either way the app tells you plainly what it did and why, so you're never left wondering where a photo went.
Photos per Page (Min/Max) — each page gets a random number of photos within this range, which is what gives the mosaic its varied, organic feel rather than a rigid uniform grid. A tighter range (e.g. 8–10) gives more consistent-looking pages; a wider range (e.g. 4–16) gives more visual variety page to page.
Paper/Page Size — set this before generating, since it directly affects how photos get cropped to fill each frame. Changing page size after the fact still works, but frames and photos will need to be re-fitted to the new proportions. See Page Setup below for the full list of sizes, including custom presets.
Orientation and Photo Order — orientation controls whether pages are portrait, landscape, or a mix; photo order controls whether photos are placed in filename order or shuffled randomly across pages.

From there, every page is fully editable — nothing about the automatic layout is locked in. Think of Generate as a fast, high-quality starting point, not a final answer.

Tip: if you don't love a particular layout, use Reshuffle to regenerate that page with a fresh random arrangement, without touching your other pages. If there are items you want to stay put while everything else moves, see Pinning & Reshuffle.

Margins tip, especially if printing via a photobook service: many commercial photobook printers trim or fold the outer edge of each page during binding, which can quietly crop a few millimetres off — most noticeably at the binding edge. If you're printing through a service like this rather than on your own printer, it's worth setting a larger-than-default margin, particularly on the side that will sit in the binding, so nothing important (faces, text, the edge of a photo) ends up lost in the trim.

Crucially, how much gets trimmed varies from one manufacturer to the next — there's no single set of margins that's right everywhere, so treat any specific values as a starting point and run your own small test print before committing to a large order.

There are two ways to approach this, and one is considerably better than the other:

Set the page size the service actually asks for (see Photobook page sizes). Because the page then matches the book, a straightforward 20 mm all round has worked well for every service I've tested. This is the approach I'd recommend.
Use a standard size such as A3 or A4 that doesn't match the book. The service has to scale and trim your page to fit, so you need noticeably larger — and uneven — margins to absorb the difference, with the biggest allowance on the binding edge.

If you're starting a new book, go with the first approach — matching the service's own size from the outset saves a great deal of guesswork about what will survive the trim. The sizes and margins I've tested for each service are listed under Photobook page sizes.

Load vs Add, and Photos vs Files

There are four buttons for getting images into your library, and they differ along two separate lines:

Load replaces your whole library — it clears everything currently loaded and starts fresh with your new selection. Add appends to what's already there, without removing anything (duplicates, matched by filename, are skipped automatically).
The Photos buttons (📂 Load Photos… / ➕ Add Photos…) pick a whole folder — every supported image inside it, including subfolders, comes in at once. The Files buttons (🖼 Load Files… / 🖼+ Add Files…) let you pick individual image files instead, for when you only want a specific handful rather than an entire folder.

So, put simply: use Load Photos to start a project from a folder, Add Photos to fold in another folder later, and the two Files variants when you'd rather hand-pick individual images than point at a folder.

Note for Windows users: the folder picker on Windows only lets you choose folders, not individual files (and won't list the files inside a folder while you browse — that's normal, not a fault). The Load Files… and Add Files… buttons are the way to select individual photos there. On Mac either style of button can pick files or a folder, so the Files buttons are just a convenience.

Finding your way around

The settings panel runs down the left, grouped into sections — Pages & Photos, Photo Fit, Spacing, Margins & Alignment, Background, Frame Border. Click any section heading to fold it away when you're not using it (the app remembers which you've collapsed), so you can keep just the controls you're working with on screen.

Your loaded photos and your page thumbnails sit in a bar along the bottom, with two tabs — Photos and Pages. Click a tab to switch, and use the ▾ button on the right to collapse the whole bar for maximum canvas space — handy on a laptop. The Pages tab is also what the Pages button in the toolbar opens.

Editing a Page

Click any frame to select it. A small toolbar appears above it with icons for:

📷 Pick photo — choose a specific photo for this frame from your library
🔄 Rotate — rotates the photo 90° at a time (only shown once a frame has a photo)
🔀 Swap — swap this frame's photo with another frame's. Any caption travels with the photo, so it always describes the picture it's attached to
⬆ Bring to front / ⬇ Send to back — change which frame sits on top where frames overlap (see below)
🗨 Caption — add or remove a handwritten caption on this photo (see Photo Captions)
✕ Delete — removes the frame entirely

Moving and resizing frames

Resize — drag the small handle at a frame's corner
Move a frame's position — hold Alt and drag the frame
Pan/zoom the photo inside its frame — scroll to zoom, drag to reposition (without Alt)
Add a new frame — use the Add Frame button, then position and size it like any other

Tip: frames snap to nearby edges and centres as you drag, for clean alignment — the snap distance is adjustable in settings if you want it looser or tighter.

Stacking overlapping frames

In a neat grid frames sit side by side and never overlap, so stacking order doesn't come up. But as soon as frames do overlap — a deliberately scattered arrangement, or the polaroid layouts — it matters which one sits on top. The ⬆ Bring to front and ⬇ Send to back buttons in a frame's toolbar move it above or below the others where they cross. Bring a frame to the front and its photo (and, in a polaroid layout, its white card) covers its neighbours instead of being covered by them.

Text Boxes

Add a text box from the toolbar, then click it to edit. Each text box has two parts:

Title (optional) — sits at the top like a heading, with its own size, bold, and italic controls, independent of the body
Body — the main text underneath, which is genuinely vertically centred within whatever space is left below the title

Style controls cover font, size, colour, alignment, line height, letter spacing, background, and drop shadow — all found in the side panel once a text box is selected.

Fonts, including handwriting and script

Alongside the usual print fonts, the picker includes flowing script faces (Dancing Script, Great Vibes, Pacifico) and relaxed handwriting ones (Caveat, Shadows Into Light, Patrick Hand) — ideal for a title on a keepsake page or a travel journal. These fonts are built into the app rather than borrowed from your system, so they look identical on Mac and Windows and work offline, and a page you build on one computer prints the same on another.

Borders

Frame Border (in settings) has two independent toggles — one for photos, one for text boxes — sharing a single thickness slider. Turn on just the one you want; they don't have to match.

Photo Captions

A caption is a short handwritten line that belongs to a single photo — a place, a date, a name — sitting in a soft band along the bottom of the picture. It's separate from a text box: a text box is a free-standing block of text you place anywhere, while a caption is attached to one photo and stays with it.

Add one — select a photo and click 🗨 in its toolbar. A caption strip appears; click it and type.
Remove one — click 🗨 again.
The caption is written in a handwriting font and sits at a consistent height on every photo, so captions line up neatly across a page.

Two things make captions behave the way you'd hope:

An empty caption prints nothing. Turning a caption on but leaving it blank costs you nothing — the band only appears in the finished page once there's something written in it. That's why some template packs switch captions on for you in advance: they're there ready to fill in, and invisible until you do.
The caption follows its photo. If you 🔀 Swap two photos, or Reshuffle the page, each caption travels with its picture rather than being left behind on the old spot — so it always describes the right image.

Tip: captions are perfect for a travel journal or photobook, where a line under each shot turns a page of pictures into a page of memories. The journal template packs come with captions ready to fill in.

Polaroid Frames

Polaroid frames dress each photo as a little instant-camera print — a white card with a wider strip along the bottom and a soft drop shadow — for a scattered, pinned-to-a-pinboard scrapbook look. The app draws the frames itself rather than baking them into a picture, which has a nice consequence: you can import your own background (a linen, cork or paper texture, say) and the white frames stay crisp on top of it.

The polaroid look comes with the polaroid template packs — restore one of those and the design arrives complete, with the frames switched on and the photos already arranged at gentle, varied angles. The Polaroid photo frames switch in the Frame Border settings is enabled when a polaroid template is loaded, so the effect stays tied to layouts that are built for it (on an ordinary tightly-packed grid the cards would overlap awkwardly, so the switch is left off there).

Because polaroid photos are meant to overlap, two features from elsewhere in the app come into their own here:

Stacking — use ⬆ Bring to front / ⬇ Send to back to control which card sits on top where they overlap.
Captions — a caption on a polaroid photo is written on the white strip beneath it, just like the real thing.

Reshuffle works as always: with the arrangement free, each shuffle deals the photos out at fresh angles and positions, so you can keep going until the scatter feels right.

Pinning & Reshuffle

Reshuffle rearranges the current page into a fresh mosaic. By default everything on the page is fair game — every frame gets a new size and position.

Pinning is how you tell it what to leave alone. Pin a frame or a text box and it keeps its exact position and size, while the mosaic re-tessellates around it instead of landing on top.

Pin a frame — select it and use the 📌 button in its toolbar
Pin a text box — select it and click the 📌 badge on its corner
Pinned items are highlighted, so you can see at a glance what's locked down

That makes it easy to anchor a fixed element — a title, a logo, a caption panel, a favourite photo — and then keep reshuffling until the rest of the page falls into place around it.

Tip: the more you pin, the less room the mosaic has left to play with. Pin enough that each remaining gap only fits a single photo and Reshuffle can still change which photo sits in each gap, but the frame sizes themselves are fixed by the space your pinned items leave behind. That's geometry rather than a fault — unpin something, or leave larger gaps, if you want more variety.

Text boxes that came from a template are pinned for you automatically, since a template's text is usually fixed branding you don't want photos landing on top of.

Page Setup

Page size options include standard sizes (A3, A4, A5, US Letter), square formats (8×8", 10×10"), and a fully custom size in millimetres. If you use a custom size often, save it as a named preset so it's available in the dropdown from then on.

Photobook page sizes

Photobook services rarely use exact ISO paper sizes. Each one specifies its own trim dimensions, so an "A3" photobook usually isn't 420×297 mm at all. What you need is the size the service asks for, entered as a custom size in millimetres at 300 DPI — and worth saving as a named preset once you've got it right, so you can reach for it again.

It's also worth establishing whether a service wants a single page or a double-page spread. A spread is two pages side by side, so it's wider. For the Photobox A3 book, for instance, a single page is 392×300 mm and the full layflat spread is 782×297 mm — and note that's not simply double, which is exactly why it pays to check the service's own figure rather than work it out yourself. Getting single-versus-spread the wrong way round is the single easiest mistake to make.

These are sizes I've tested myself:

Service	Page size	Margins
Photobox — A3, single page	392 × 300 mm	20 mm all round
Photobox — A4, single page	300 × 216 mm	20 mm all round
Photobox — A3 layflat spread	782 × 297 mm	20 mm all round
Colorland — A4	300 × 216 mm	20 mm all round
Colorland — A3	423 × 303 mm	20 mm all round
Printerpix — A3	400 × 300 mm	20 mm all round
Mixbook	US Letter and square formats	20 mm all round

Photobox and Colorland both offer A3 and A4 books; the Photobox A3 single page also scales down neatly to fit their A4, so a layout built at A3 can be reused at the smaller size. Mixbook works with the standard US Letter and square sizes already in the page-size dropdown, so there's no custom size to set up at all.

On a double-page spread, remember the binding runs down the middle rather than along an outer edge — so it's the centre of the page you want to keep faces and text clear of, not just the outside.

Verify with a test print before committing to a big project. Photobook services change their book sizes and their own layout software from time to time, so a size that worked perfectly well last year may not be right today. The figures above are a starting point from my own testing rather than a guarantee — and they're worth re-checking against whatever your service currently specifies. Ordering a single test page, or one small book, costs very little next to discovering a sizing problem after you've laid out two hundred pages.

Margins, gap between frames, and snap distance are all adjustable, and can be saved as your personal defaults (⚙ Defaults) so every new project starts exactly how you like it. If you're printing through a photobook service rather than at home, see the margin/binding tip in Getting Started before settling on your margin values.

Margins, gaps and borders are real measurements

Each margin slider shows its size in millimetres underneath it. Those are genuine physical measurements: a given slider value is the same real-world size whatever page size you're working at, whatever screen you're on, and whatever size the app window happens to be when you set it.

That matters most on a long project built over several sittings — a photobook assembled across months, perhaps on more than one computer. Every section you produce gets identical margins, gaps and border widths, so the finished book stays consistent from cover to cover rather than drifting section by section.

Page background

The page background isn't limited to black or white — choose any colour you like. Frame border contrast adjusts automatically, so borders stay visible against whatever background you pick.

You can also import your own background image. It's scaled to cover the page and sits behind the mosaic, and it's baked into the exported JPEG — so what you see on screen is what you get in the file.

Photo fit — fill the frame, show the whole photo, or jigsaw

Photo fit (in the Photo Fit panel) decides how each photo sits in its frame:

Fill frame — the default — crops each photo so it completely fills its frame: no gaps, but the edges may be trimmed.
Fit whole photo — shows the entire photo inside the frame with nothing cropped, letting the page background show around it wherever the photo's shape doesn't match the frame's. Reach for it when the whole of every shot matters, or pair it with a background colour or image for a deliberately airy look.
Jigsaw — whole photos, no gaps — sizes every frame to its photo's own shape, so your pictures fit together whole, edge to edge, filling the page with no gaps and nothing cropped. It's the one to reach for on a poster or a photo-packed page. It flows around any pinned titles or text, and Reshuffle re-flows the jigsaw into a fresh arrangement.

Cropping less in the mosaic

When you're using Fill frame, three settings (in the Photo Fit panel) make the cropping far kinder to your photos:

Match photos to frame shapes — assigns each photo to the frame that best matches its shape, so landscapes land in wide frames and portraits in tall ones. This roughly halves how much is cropped, and prints come out sharper because photos are scaled up less. It applies when you Generate or Reshuffle.
Keep the subject in view — when a photo is cropped to fill its frame, the crop is centred on the main subject (a face, the focal point) instead of the middle, so subjects aren't sliced off at an edge. It's analysed entirely on your own computer — no photo ever leaves the device.
Maximum crop — a slider that caps how much Fill is allowed to crop. At 100% it fills as it always has; lower it and any photo that would be trimmed harder than the limit shows a little background instead of being over-cropped. At 0% nothing is cropped at all (the same as Fit whole photo).

For zero cropping with no gaps either, use Jigsaw above; these three are for when you want to keep the classic mosaic look but treat your photos gently.

Coverage — let the background show

By default the mosaic fills the whole page. The Coverage slider lets you shrink it so more of the page background — a colour, or your imported image — shows through between the photos. At 100% it fills the page exactly as it always has; lower it for an airier, more spacious result. It pairs naturally with a background image or a bold background colour.

Pinned frames keep their full size (see Pinning & Reshuffle), so you can hold a title photo large while everything else breathes around it.

Coverage takes effect when you Generate or Reshuffle, and there's an ↔ Apply coverage to existing pages button to try different amounts on a layout you've already built.

Changing layout settings without regenerating

Pressing Generate rebuilds everything from scratch, which throws away the arrangement you've worked on. Five buttons let you change your mind about a setting and apply it to the pages you already have instead — your photos, their zoom, pan and rotation, and all your text stay exactly as they are:

↔ Resize pages to this size — moves your existing pages onto a different page size.
↔ Apply margins to existing pages — re-fits the frames to new margins.
↔ Apply spacing to existing pages — re-spaces the frames to a new gap. Tighten it and every frame grows into the space released; widen it and they shrink back.
↔ Apply coverage to existing pages — shrinks or grows the mosaic to reveal more or less of the page background, keeping your arrangement. Pinned frames stay full size.
↔ Tidy frame alignment — see below.

All five can be undone, so they're safe to experiment with.

Resizing to a different page shape

Where the new size has the same proportions — A4 to A3, for instance — the result is lossless: everything simply scales up or down, and it happens straight away.

Where the new size is a different shape — A4 to a square format, say — the layout can't simply scale, so the app asks how you'd like it filled:

Re-flow layout (recommended) — your photos are rearranged into a fresh mosaic designed for the new shape. This gives the best-looking result with nothing to tidy up afterwards, but any manual arrangement of unpinned frames is replaced.
Keep my arrangement — your existing layout is stretched to fit. Photos are re-cropped rather than distorted, but frames change shape, which is more noticeable the bigger the difference in proportions.

Pinned frames and text are preserved either way, so pin anything you want kept before resizing.

Tidy frame alignment

The mosaic is built by repeatedly dividing the page, and each division is made independently — so occasionally two frames end up with edges a couple of millimetres apart where the eye expects a straight line. It's too small to look deliberate and just reads as untidy.

↔ Tidy frame alignment nudges those near-miss edges into exact alignment. Nothing is rearranged and pinned frames don't move — only edges that were a hair out shift at all, and running it a second time changes nothing. It's most useful on projects built with an earlier version, since newer pages are laid out with this correction already applied.

Saving Your Work

There are three distinct ways to save, and they solve different problems:

Option	What it saves	Best for
Save	The layout only, as a small JSON file — photos are referenced by filename, not included	Quick saves during a session on the same computer
Archive	The layout and a full copy of every photo used, bundled into one ZIP	Moving a project between computers, or long-term safekeeping
Save as Template	The layout only, with every photo reference deliberately removed	Reusing a favourite design with a completely different set of photos

Why Archive is often the better choice

A plain Save is small and fast, but it only remembers your photos by name — it depends on those exact files still being in the same folder, with the same names, whenever you come back to restore it. If you reorganise your photo library, rename files, or move to a different computer, a plain Save can leave you hunting for the right folder.

Archive avoids that problem entirely, because your photos travel inside the file itself. Restoring an archive doesn't require finding anything — everything needed is already there in the ZIP. That makes it the more genuinely reliable option, especially for a project you care about keeping long-term, or one you might want to reopen on a different computer.

The trade-off: because Archive physically includes every photo, the file size scales with your library. A project built from a few dozen photos archives to a modest file — but a project using hundreds of full-resolution photos can produce a genuinely large ZIP file, taking longer to create and more disk space to store. For very large libraries, a plain Save (paired with keeping your original photo folder somewhere safe) may be the more practical everyday choice, with an occasional Archive as a more durable checkpoint.

A reasonable approach: use Save for your regular day-to-day working file, and make an Archive once a project is finished, or before any major reorganisation of your photo folders — that way you always have one fully self-contained, future-proof copy, without paying the file-size cost on every single save.

Templates

Save as Template stores a layout with every photo reference deliberately stripped out — the design, the text, the pinned branding, but none of your pictures. Restore it later and you get that design back, empty and ready for a fresh set of photos.

From Template

🗂️⚡ From Template takes that further: it lays the template's design down on page after page and pours your whole library into the frames, filling as many pages as it takes to place every photo.

Every page uses the same design — the same frame shapes and positions, and the same branding — so the run reads as one consistent book rather than a set of unrelated pages.
The app works out how many pages it needs from how many photos you've loaded and how many frames the design has, so nothing is left unplaced. The last page is simply left part-filled if your photos don't divide evenly.
The template's text and pinned items appear on every page — a title, a logo, fixed branding — exactly where you put them.

It's the quickest way to turn a folder of photos into a long, consistent run of pages — a travel book, a yearbook, a catalogue — in a single step.

Tip: want variety between pages rather than a fixed grid? Leave some frames unpinned, then press Reshuffle on any page to re-tessellate those frames into a fresh mosaic around whatever you've pinned — the app's original no-fixed-grid behaviour, framed by your pinned design.

Ready-made template packs

You don't have to build a template from scratch. Ready-made template packs to restore and build from include film-style contact sheets, scattered polaroid layouts, and travel-journal / instant-photobook designs — a large "hero" photo with a flowing script title and supporting shots, each with a caption ready to fill in. Restore one, load a folder of photos, and From Template pours a finished multi-page book in seconds.

Chat Book

Turn a WhatsApp or iMessage conversation into a printed book — a warm keepsake of a family or group chat, or a clean numbered transcript for your records. The chat is read straight from the export file on your own computer; nothing is ever uploaded.

Step 1 — export the chat

There are two routes. Which one you use decides how many of your photos end up in the book.

WhatsApp's own "Export chat" — quick and free, but leaves older photos behind. On your phone, open the chat you want, then:

iPhone: tap the contact or group name at the top → scroll down → Export Chat.
Android: tap the ⋮ menu → More → Export chat.

When asked, choose Attach Media so your photos are included. Save the export to your computer, or AirDrop / email it to yourself — you'll get either a .zip or a _chat.txt file; either one works. WhatsApp only bundles roughly the most recent few hundred photos and videos in an export, so in a chat that goes back years, older pictures are simply not included — that's a WhatsApp limit, not something the app can undo. Where a photo is missing, the book shows a small "photo not included" marker, which you can hide.

iMazing's "Text" export — the complete export, and it covers iMessage. iMazing is a well-known Mac and Windows app for managing an iPhone or iPad. Because it reads the chat and its media from your device's own backup, it isn't bound by WhatsApp's in-export media cap — it can give you the whole conversation with all of its photos, and it can export iMessage chats too (Apple's own Messages app has no export button of its own), which also covers any plain SMS/MMS texts in the same thread. In iMazing, open the conversation and export it as Text — it saves a .txt file and a folder of the chat's photos and videos alongside it; keep the two together.

Either way, it stays private. Whichever route you use, the app reads the file entirely on your own computer and never uploads your conversation. iMazing likewise works from your own device and backup on your own machine.

Step 2 — import it into Mosaic

Click 💬 Chat Book… and pick the export file you saved (a WhatsApp .zip / _chat.txt, or an iMazing .txt). For an iMazing export the app will also ask you to choose the attachments folder it saved next to the text file, then matches every photo to its message automatically. The Make a Book window then opens, where you choose how the book should look.

Step 3 — choose Keepsake book or numbered transcript

Keepsake book — chat bubbles — the chat laid out like it looks on your phone: rounded bubbles, names, date headers and photos, with a designed cover. This is the one for a gift or a memento.
Transcript — numbered record — a clean, formal, paginated document of the whole conversation, with attached photos and PDFs rendered inline. Reach for it when you want a tidy record rather than a keepsake.

You can also pick a page shape — portrait, landscape or square — to match the photobook size you'll order.

Cover, themes and yearly volumes (Keepsake book)

Cover — set an editable title and subtitle (the subtitle defaults to the chat's date range) and choose a hero photo for the front.
Theme — pick a colour theme for the whole book; Restyle swaps it in one step without touching any of your edits, so it's worth trying a couple.
Yearly volumes — if the chat spans several years, split it into one book per year and build a matching set — lovely as a gift. Leave it as a single book for a shorter chat.
Stats page — an optional "chat in numbers" spread: who sent the most messages, your busiest day, the emoji you all overuse, and more.
People photos — give each person in the chat a photo, used on the cover and beside their messages; anyone without one gets a coloured monogram of their initials.

Naming people the export didn't name

The app resolves everyone's name where it can. Two cases need a quick manual fix, both done right in the Make a Book window:

Phone numbers instead of names. If someone shows up as a bare phone number, type their real name into their name box. If the same person appears twice — once as a number and later under their saved contact name — rename the number entry to exactly match the contact name and the two merge into one person throughout the book, with their messages and counts combined.
@mentions that show a number. In some newer WhatsApp group chats, an @mention in the export contains only a numeric ID rather than the person's name. The app flags these under Name these @mentions so you can put a name to each one manually; once named, the mentions read properly through the whole book.

After it's built

Your book is now an ordinary Collage project — every page can be adjusted, and you can change the theme, add or move photos, or edit text just as you would any other layout. When you're happy, export it as a single print-ready PDF (or JPEG), like the rest of the app, and take it to any printer or photobook service. You own the file, so you can reprint or restyle it any time.

iMessage photos on Windows. iMessage photos are usually in Apple's HEIC format, which the Windows version can't decode (they work fine on a Mac). If you're on Windows, turn on iMazing's "Convert HEIC to JPEG" option when you export — every photo then comes across as a normal JPEG and imports without a hitch.

Restoring a Project

Use Restore to reopen a saved session. If any referenced photos aren't currently loaded, the app asks you to select the folder containing them — and if your project drew photos from more than one folder, it keeps asking, letting you load folder after folder until everything's found (or you choose to continue with gaps).

Missing photos

If some photos genuinely can't be found, the sidebar shows their exact filenames under a "Missing" heading — rather than just a bare count — so you have something concrete to search for.

If you later load or add photos that match a missing name, they're automatically placed back into their original frame, at the same crop, zoom, and rotation they had when you saved — no manual re-placing needed.

Tip: Archive sidesteps all of this, since there's never anything to go looking for — see the Saving section above.

Export & Print

Export Page and Export All save your pages as JPEG images (a ZIP of JPEGs when exporting multiple pages).

Print (labelled Save for Printing in the app) prepares your page(s) as JPEG and asks where to save them — open the saved file(s) in your photo viewer (Preview on Mac, Photos on Windows) and print from there with Cmd+P (Mac) or Ctrl+P (Windows). This two-step approach is necessary because neither platform's native app framework allows an app like this one to open a live print dialog directly, but it gives you full control over paper size and scaling through your photo viewer's own print options.

Save as PDF

The ⬇ PDF button saves all of your pages as a single, print-ready PDF — ideal for uploading to a photobook service (Blurb and similar) or handing to any printer. When you export, you're asked whether to add bleed:

With 3mm bleed — for a photobook service or professional printer. Coloured backgrounds and full-bleed photos are extended past the trim edge, so there are no white slivers after the pages are cut to size.
No bleed — for printing at home, where the page is used exactly as laid out.

The PDF is written straight to disk as each page is finished, so even a very large photobook — hundreds, or well over a thousand, pages — exports steadily without running the app out of memory.

Transparent backgrounds

Tick Transparent background on export before exporting to leave the page background empty instead of filled — useful for overlaying a page on something else, printing onto coloured or textured stock, or further design work.

Images export as PNG in this mode (rather than JPEG), because PNG can carry transparency and JPEG cannot.
PDF keeps the page background transparent too.

Leave the box unticked for normal opaque pages (JPEG images, and a solid background in the PDF).

Rounded photo corners

Set Photo corner radius (mm) to round the corners of your photos for a softer, more modern look. It's measured in millimetres, so it prints at a consistent physical size whatever your page size, and it applies both on screen and in every export — JPEG, PNG and PDF. Set it to 0 for square corners.

Tips for Large Photo Libraries

The app has been tested with libraries in the range of 1,000+ photos across 400+ pages, so don't hesitate to work at real scale. A few things worth knowing at that size:

Generating and exporting hundreds of pages takes real time — the progress bar reflects genuine per-page work, not a placeholder.
Photos are automatically scaled to properly fill their frame even on pages you never manually open — you don't need to click through every page before exporting.
If exporting produces a different page count than expected, the app will tell you directly rather than silently shipping an incomplete result.
Archives and multi-page exports are written straight to disk as they are built, rather than being assembled in memory first — so memory use stays low and steady however large the export becomes.

Roughly how long should this take?

Saving, Archiving, and Exporting all write to disk at a similar rate — measured at roughly 10–11 MB/s during testing. That figure is IPC round-trip overhead, not raw disk or CPU speed, so it's a reasonable planning number across different machines.

Photos in library (~6MB each)	Approx. Archive size	Approx. write time
100	600MB	~1 minute
500	3GB	~5 minutes
1,000	6GB	~9–10 minutes
1,500	9GB	~14 minutes

For Export Page, Export All, and Print, a single rendered page at 300 DPI is far smaller than a full Archive — roughly 8–16MB for A4 (2480×3508px) and 18–30MB for A3 (3508×4961px), depending on how busy the layout is. At the write speed above, that's only 1–3 seconds of actual disk time per page. For a large multi-page export, most of the total time is spent rendering each page (drawing every photo into its frame and encoding the JPEG) rather than writing it to disk — rendering speed scales with photos-per-page and your computer's processor, not disk throughput, so it isn't covered by the figures above.

Note: these figures come from real measurements on one machine and will vary with your own disk, processor, and how visually complex each page is — treat them as a rough planning guide, not a guarantee.

Troubleshooting

Red "⚠ DPI" badge on a photo

This means that photo is being stretched beyond what looks sharp at print size in that particular frame — the badge shows the approximate effective resolution. Zoom out slightly, use a higher-resolution photo, or use a smaller frame or page size.

HEIC photos not loading

HEIC/HEIF (the default iPhone photo format) requires native decoding support. macOS provides this, so HEIC/HEIF photos work normally on Mac. Windows does not, so on Windows these photos are skipped (and, when restoring an Archive, the app will tell you how many were left blank for this reason). If you're seeing HEIC photos skipped, convert them to JPEG first — most photo apps offer this as an export option.

A frame's photo looks off-centre with a border on

This was a known issue in earlier versions, now fixed — text and photo positioning both account for border thickness. If you're seeing this, make sure you're on the latest version.