Today i tested my blue thermal paper. The printer has a sensor for checking if paper is inside the paper and it looks like it only accept white thermal paper. I hope not only a special brand, but i have to test this too.
So i made a little hack, the sonsor sees know always the right paper:
...and here a comparison. But it dont look good, i dont think i will use it. The picture look somehow wrong, i think the paper is to thick.