Why this goes wrong so reliably
Transfer printing is the one use of a reflection where the mistake is physical. A wrongly reversed digital file is an inconvenience; a wrongly reversed transfer is a consumed sheet, a marked garment and, in a sublimation blank, a ruined object. The operation is not difficult. What makes it error-prone is that three separate systems can each reverse the artwork — the file, the printer driver, and the press itself — and only an odd number of reversals produces the right result.
So the useful discipline is not learning which method needs mirroring. It is deciding where the reversal will happen, doing it there, and confirming that nothing else is doing it too.
The order of operations
- Decide from the direction of the printed face. Every rule about mirroring for transfers comes from one fact: whether the ink ends up touching the garment or facing away from it. Face down means the press reverses your artwork, so reverse it first. Face up means leave it alone.
- Finish the artwork before you reverse it. Reversing commutes with resizing but not with cropping or with adding anything positioned by eye. Do the composition, then reverse, so the last thing you look at is the thing that gets printed.
- Reverse the file once. On the horizontal axis for a press that loads from the near edge, which is nearly all of them. Save it under a name that says so, because a reversed file and its original are indistinguishable in a thumbnail grid at the size a file manager shows them.
- Turn off the driver reversal. Look for mirror image, flip horizontal, or an iron-on transfer media type in the print dialogue and switch it off. Some drivers enable it silently when the paper type is set to transfer film, which is the single most common cause of a design coming out backwards after it was correctly reversed.
- Print at exactly one hundred per cent. Scale to fit, fit to page and shrink oversized pages will all resize the sheet by a few per cent without saying so. Measure the printed design against the intended placement before any heat is applied.
- Proof on plain paper. One sheet of ordinary paper, held up to a window with the printed side away from you, shows exactly what the garment will show. It costs a sheet of paper and catches every ordering mistake in this list.
The settings that undo your work
Three settings account for nearly every reported failure. The first is the driver mirror option, which is often attached to a media type rather than presented as its own control, so choosing the transfer-film paper setting can turn it on without any visible change. The second is page scaling, which is enabled by default in most operating system print dialogues and in almost every browser print path. The third is a photo-enhancement or vivid-colour option, which will not reverse anything but will shift the colour away from whatever you proofed.
None of the three is visible from a file. They belong to the dialogue between your computer and your printer, and the only way to see what they did is to look at a printed sheet. A plain-paper proof held to the light, printed side facing away, is a complete check of both the reversal and the size, and it is the step most often skipped.