Stackfill

StackFill is a Parameter product built for a problem we kept meeting in print-industry client work. It turns an approved print PDF into a fillable template: mark which fields are editable, lock the rest, and hand customers a link. They personalise, they pay, and the output is built from the artwork that was already approved.

The hard part is colour. Standard web tooling converts artwork through RGB and quietly discards CMYK data, which is the difference between a proof that looks correct on screen and a print run that does not. StackFill is CMYK-aware and trim and bleed aware, and preserves locked artwork where the source supports it.

It exists because we needed it and nothing off the shelf did the job. That is the honest test for custom software: not that a product would be nice to own, but that the alternative genuinely does not work.