Print Bleed & Safe-Area Generator
Your printer wants artwork that runs past the cut line. Set your finished size and DPI, choose a bleed width, and this extends your image outward by mirroring its own edges — so the extra margin looks like a continuation of the artwork rather than a smear. Preview the cut and safe lines, then download a clean PNG. Your file never leaves your device.
Why a print file has to be bigger than the product
Cutting is mechanical and mechanical things drift. A stack of paper shifts a fraction under the blade, a heat press lands a shade off centre, a sheet of vinyl stretches as it feeds. If your artwork stopped exactly at the finished size, that drift would show up as a hairline of bare white along one edge — the single most recognisable sign of an amateur print job. Bleed is the insurance: you supply extra artwork past the cut line, the blade lands somewhere inside that extra, and the printed colour runs right off the edge no matter where it landed.
The mirrored fill this tool uses solves the awkward part. Most artwork was not designed with a spare margin, so there is nothing to extend outward with. Reflecting the outermost strip of the image back on itself produces a margin whose colour, texture and grain continue the artwork seamlessly — a wood grain stays wood grain, a gradient keeps going in the right direction. It only ever appears in the part of the sheet that gets cut off, so the mirror seam is never visible in the finished piece. Stretched edge pixels are the cruder alternative and work fine on flat colour; a solid fill is right when your artwork already sits on a plain background.
The safe margin is the mirror image of the same problem, pointed inward. Because the cut can land anywhere in the bleed zone, anything close to the trim line might be shaved. Text, logos and faces therefore need their own buffer inside the cut, and that buffer is what the safe line marks. Nothing enforces it: the safe line is drawn in the preview and never written into your artwork unless you deliberately ask for a marked-up proof.
Working out the pixel size
Every number here resolves to pixels through the DPI you set. An 8 × 10 inch print at 300 DPI is 2400 × 3000 px of trim area. A 0.125 inch bleed is 37.5 px, rounded to 38, added on all four sides — so the file you send is 2476 × 3076 px. That total is displayed as you type, which is the fastest way to catch a mismatch: if the number looks nothing like what your printer's template asks for, one of your inputs is wrong before you have wasted an export. If the DPI half of that maths is what trips you up, DPI vs PPI explained, with the print size formula covers it properly.
Mirror, stretch or solid: picking the edge fill
The Fill the bleed with menu offers three ways to manufacture a margin that was never in your artwork. They are not equivalent, and they fail in different ways.
Mirrored edges — best for almost everything
Each side of the trim area is reflected outward: the strip of artwork touching the cut line is flipped and drawn into the bleed, with the four corners flipped on both axes so they meet cleanly. Because the reflected pixels are your own artwork, colour, texture, grain and noise all continue across the trim line at the correct scale, which is why nothing about the margin looks bolted on. It suits photographs, painted textures, gradients and anything with visible material. Its failure is specific: a face, a straight horizon or a piece of text sitting close to the edge gets duplicated as a recognisable reflection, and on a wrapped product where part of the bleed stays visible that reads as a mistake. If the bleed you ask for is wider than the artwork, there is no strip left to reflect — the tool caps the reflection and stretches it across the remainder, and warns you that it has done so.
Stretched edge pixels — acceptable on flat colour only
This takes the single outermost row and column of the trim canvas — literally one pixel deep — and pulls it out to the bleed edge, with each corner smeared from one lone corner pixel. On a plain background that is exactly right, because one pixel of a flat colour tells you everything about that edge. On anything with detail it is obviously wrong: a stripe or a repeating pattern becomes a set of parallel streaks running off the sheet. Use it when the outer few millimetres of your artwork are already a single uninterrupted tone.
A solid colour — only when you can match the edge exactly
The whole canvas is flooded with the colour from the swatch before the artwork is placed on top, so the bleed is that colour and nothing else. This is invisible in the finished piece under one condition: the artwork's own edge is already that colour. Match it with a picker against the real file rather than by eye — a swatch that is a couple of values off produces a faint band just outside the cut line that shows up the moment the blade drifts outward. It is the right answer for a logo on white, a card with a flat coloured border, or any layout that was designed on a solid ground. It is also the fallback the tool suggests when your bleed is too wide to mirror.
None of the three beats going back to the design file and exporting with real bleed. Bleed drawn by the designer is artwork; bleed synthesised from the edges is a plausible guess that happens to get cut off. Extending a document by an eighth of an inch and pulling the background out to the new boundary costs a minute in any layout program. This generator exists for the other case — the flattened JPEG a client sent, the file whose layered source is on a dead laptop, the stock image you licensed as a finished raster. If you are building a print file from scratch, our guide to print-on-demand image requirements and sizes covers what to build in from the start so you never need this page.
Frequently asked questions
How much bleed do I actually need?
Ask the printer — it is the one number you should never guess. That said, 0.125 in (an eighth of an inch) is the common default in the US and 3 mm is the common default where metric paper sizes are used; they are close enough that either is a reasonable starting point for paper goods. Large-format work, wrapped canvas and anything cut by hand routinely need far more, sometimes an inch or two, because the wrap or the tolerance is that much bigger.
Will the mirrored edge show up in my printed piece?
No, not if your trim size is right. The mirrored strip lives entirely outside the cut line, which means it is physically removed during finishing. The one case where it becomes visible is a wrapped product — a gallery-wrap canvas folds part of the bleed around the frame edge. For those, set the bleed to the full wrap depth and check the preview: if the mirrored region contains something you would not want on the side of the frame, extend your artwork properly instead of relying on the mirror.
My image is a different shape to my print size. What happens?
It is scaled to cover the trim area and centred, so the shorter dimension fills completely and the overflow on the longer one is cropped off. That is the behaviour you want for a bleed file, because any other choice would leave blank strips inside the cut. If the crop is taking something important, adjust the trim ratio or re-crop the source first — the stats panel shows you the trim pixel size to aim for.
Is my artwork uploaded anywhere?
No. The image is decoded, mirrored and re-encoded locally with the HTML canvas, and the download is generated inside the page. Nothing is sent to a server and nothing is stored. After the page loads, the tool works with no connection at all.