I have two kinds of illustration stuff available: personally made and printed somewhere else on-demand. These are two completely different things: I don’t sell any versions of my signed (or signed and numbered) prints in on-demand stores.
Personally made, signed (and sometimes numbered) prints and drawings are made 100% by myself from start to end. I sell this stuff personally and in some selected (real life) shops. At the moment you can request these prints only by emailing me, but my Etsy shop will be open again at sometime (hopefully soon).
My illustration images are also available as printed on-demand illustration merchandise – in posters, t-shirts and mugs. These illustrations are designed by me, but printed, handled and posted by someone else. In my Zazzle/Kuvituksia shop I sell mostly character based merchandise like posters and t-shirts and in Society6 shop some other stuff too. I have also plans to open other shops for my on-demand stuff… soon.