I did some more experimenting with acrylic paint and fabric. Both pieces are A4 size (8,5"x11") and started out as the same parfait dyed fabric. On the top one I stitched a number of small pleats following the Fibonacci rules. When everything was stitched I painted it with Golden acrylic paint and let it dry. Next day I removed the stitching and ironed the fabric. This is how it looks now:
On purpose my stitching lines were not straight. Same with this piece. Here the stitching lines were not numbered and again Golden acrylic paints were used. Without adding medium the hand of the fabric changes, but as I create wall hangings it does not matter. These samples are small, but I think I will be using this technique on bigger pieces too. Someday in the - hopefully - near future.