The sizing on the unwashed muslin makes a BIG difference. I'm thrilled! I can create precision lines and shapes without any bleeding. The only problem was a dark ring showed up when filling in shapes (see arrows on the first picture). It didn't happen when I worked very quickly by outlining and filling in the shape all in one go so I was working wet-on-wet. When I outlined the shape first then went back and filled it in, the ring appeared because the outline was dry by then.
Same result on the silk organza regarding the ring. But no precision is possible on the silk; they bleed and spread intensely.
I'm excited by the watercolour effect on the silk! And I'm thrilled that I can use these on cotton! Other than the ring issue I like these more than the Zig 'Writer' Memory System markers because these colours are far more saturated on fabric, they act like ink.
Permanent when heat set with an iron.
|BIC Mark It markers on unwashed cotton muslin. Note the arrows pointing out the dark ring|
|BIC Mark It markers on silk organza. Note the arrows pointing out the dark ring|