Page size

The finished trim size is measured in millimetres and compared against the sizes printers keep stock and cutting formes for — the whole A series from A7 up to A0, DL, US Letter, an 85 × 55 mm business card and three square sizes — in either orientation. An exact match passes, and the result names which way round it is: "A4" on its own has sent more than one landscape design to press as a portrait one.

Anything else is a warning rather than a failure, because plenty of jobs are deliberately an odd size; it just costs more, since the sheet has to be trimmed down. Sizes within about a centimetre of a standard one are called out by name, orientation included, because a near-miss is nearly always an accident — a flyer built on a US Letter page instead of A4, or a design started at 152 × 216 mm from a US preset.

For an image upload you set the finished size yourself: every one of those sizes is in the dropdown alongside a custom option, with a portrait/landscape switch that turns any of them. Changing size keeps the orientation you were already in, a landscape photo starts as a landscape job, and a square offers no switch because there is nothing to turn.

Bleed

For a PDF, the file's trim box is compared against its bleed box (or media box, if no bleed box is set) and the gap is measured on all four sides. 3 mm or more on every side is a pass. PNG and JPG files carry no page geometry at all, so they're always treated as flat, bleed-less artwork.

Crop marks

The page's own drawing instructions are scanned for short marks sitting near each trim corner. It's a best-effort read, not a guarantee — some layouts come back as "couldn't verify". Either way, every print-ready PDF gets its own fresh, correctly placed crop marks, so this never blocks you.

Resolution, fonts and colour

For a PDF, every image actually placed on the page is found, its effective dpi worked out from its pixel size and how large it's drawn, and each font checked for embedded outlines (the standard 14 print/PDF fonts are exempt). Colour mode is read from how the artwork is built. For PNG and JPG uploads, resolution is worked out from the pixel size against the trim size you set, and colour mode is read straight from the file.

Choosing which checks run

All six run by default. Each has a switch above the queue, so you can leave off the ones you already know are fine. On a large PDF the image scan is most of the wait, so switching resolution, fonts and colour off together skips it entirely rather than doing the work and hiding the answer.

A check that's off is reported as not run, never as a tick, and the report names what was skipped underneath. Switching it back on re-reads the file and measures it properly — you never get a stale or invented result. Whatever you switch off, the print-ready PDF still gets its bleed and crop marks: the switches decide what gets reported, not what gets built.

What it won't try to fix

Low resolution and missing fonts are flagged, not corrected. A stretched low-res image or a guessed font substitution does more harm than good — those need sorting at the source, in the file that made the artwork. So every check in the report opens into three things: what we looked at, why a printer cares, and the actual steps to fix it — with the Canva version written out separately, since Canva hides most of these settings in places you would not think to look.

How bleed gets added

Your artwork is never stretched or scaled. If a file already has proper bleed, that artwork is carried straight through untouched. If it doesn't, the design is placed at its true size and the missing bleed is built out of the artwork's own edges — so each side keeps its own colours. A design with a green top and a blue bottom bleeds green above and blue below; a photo carries its own colours out past the cut.

The narrow strip of colour along each edge is stretched outwards to fill the bleed — a fraction of a millimetre of artwork, so what gets extended really is the colour at the edge. It is all cut away at the guillotine anyway: it exists purely so the blade never finds white paper. A single flat colour is available instead where that suits the artwork better, and for anything with elements that must land exactly on the edge, extending the bleed by hand in your design software still gives the cleanest result.

How much bleed. 3 mm is the UK and EU standard and the default here. You can also choose 5, 10 or 20 mm per file: large-format work, anything mounted or stretched over a frame, and some finishing processes want considerably more than a flyer does. Whichever you pick, the finished size stays exactly the same — only the sacrificial margin around it changes.

What comes out

A PDF is rebuilt as a PDF, not as a picture of one. Your page is copied across whole — live text, vector artwork, and placed images at exactly the resolution they arrived with — then moved so the trim lands correctly and given its bleed and marks. Nothing is flattened, downsampled or rasterised, so the file opens as an editable page in Illustrator or Acrobat rather than a locked group, and it prints as sharp as the press can manage at any output resolution.

An image upload can't become vector — a photo is pixels whatever you wrap it in — but it is placed at full resolution with no resampling, and the report tells you the true dpi at your chosen finished size. Where that lands under 300, the page says so and offers the one fix that actually works: the largest finished size at which those pixels genuinely make 300 dpi, applied in a click. It will not upscale to hit the number, because that changes the number and not the print. Where CMYK conversion is used, the pixel data is compressed losslessly, so the file stays a sensible size without losing anything.

RGB → CMYK conversion

Most simple converters treat ink as the arithmetic opposite of light — cyan is whatever red isn't. It's quick, and it's wrong: real cyan ink prints as (0, 173, 239) rather than a pure cyan, and magenta over yellow gives a warm red, not the pure red the sum predicts. Invert the wrong model of ink and every colour lands near but not right, which is why converted artwork so often comes back looking flat.

Artwork Fixer works from a measured model of how process inks actually behave on coated stock, and for each colour finds the ink mixture that lands closest to it. On a test chart of neutrals, brand colours, skin tones and foliage, colours land within about 1% of the original, against roughly 7% for the arithmetic method. Black is kept out of the highlights and midtones so colour stays clean, total ink is held to 300% so the sheet can dry, and solid blacks get cyan, magenta and yellow underneath — a rich black, because black ink on its own prints as a dark grey rather than a black.

Two honest limits. Colours brighter than CMYK ink can physically reach — the electric blues and greens a screen can show — are mapped to the closest printable colour; that ceiling is the press, not the tool. And this isn't a full ICC conversion against a named press profile, so if your printer has specified FOGRA39 or GRACoL, converting in Illustrator or Acrobat with that exact profile is still the last word.

Large files

Uploads go up to 1 GB. Past about 300 MB you'll see a warning, because the file has to be held in memory while it's read and a browser tab that runs out doesn't fail politely. That ceiling is the browser's, not the tool's — the message says so plainly rather than pretending otherwise.

1. Set the size before you start

Create the design with Custom size in millimetres at the finished size you actually want — 210 × 99 mm for a DL flyer, 85 × 55 mm for a business card. Width first, so 297 × 210 for A4 landscape. Resizing later is a Pro feature, and scaling a finished design to fit a new page softens every image in it. Watch for the US presets: "Flyer" can land you on 8.5 × 11 in, which is not A4 and will be flagged here as a near-miss.

2. Turn bleed on, then actually use it

Under File → Settings, tick Show print bleed. A dashed line appears just outside the page. Ticking the box does nothing on its own — you then have to drag every background, photo and block of colour out to that line, and pull text and logos a few millimetres inside the page edge so a drifting cut can't clip them.

3. Export as PDF Print, with marks and bleed

In the download menu choose file type PDF Print — not PDF Standard, and not JPG or PNG — then tick Crop marks and bleed. That single tick is what puts both the trim marks and the bleed area into the file. Without it you get a page cut exactly at the finished size, which is the single most common reason artwork gets sent back.

4. Colour: the one you can't fix in Canva

Canva exports RGB at every plan level. There is no CMYK option, and no setting that adds one. Left alone, the conversion happens somewhere at the press and the brightest colours come back duller than you approved, with near-blacks printing as a washed-out grey.

That is what the Convert to CMYK tick here is for. Export from Canva as usual, drop the file in, convert, and you get to see the shift before it is on paper — with blacks built as a rich black rather than black ink alone.

5. Check your images before you trust the canvas

Canva previews at screen resolution, so a photo can look perfectly sharp on the canvas and still be far too small to print. Anything saved from a website or a social post is almost certainly 72 dpi. As a rule of thumb an image needs roughly 12 pixels for every millimetre it will be printed across — so a photo running the full 210 mm width of an A4 page wants about 2,500 pixels.

Already exported it the wrong way?

You don't have to go back and redo it. Drop the Canva PDF in here and Artwork Fixer will add the bleed from the artwork's own edge colours, add proper crop marks, set the trim and bleed boxes, and convert the colour — without stretching or re-rendering anything you made.