I had some fun dyeing this past weekend using weld on different substrates and shades of fiber. Weld is just the greatest dye to work with; read more about weld at www.longridgefarm.com/dyetips.asp
I also dyed and untied my first shibori piece, the ties are bound with one connecting thread giving many evenly spaced spots that will resist the dye. The top photo is a bit blurry, but you can see the ties and where I have undone, the white pointed tips starting to show. Once the piece is dyed and dried completely, the ties are carefully undone by pulling the fabric away from itself. The result is beautiful, I think. I dyed it initially with weld and then overdyed with indigofera tinctoria one quick 5 second dip.
Left to right in the picture: silk strips in weld only, dark gray wool in weld only, white silk dyed in weld and overdyed with indigo, and silk strips in weld with an indigo overdye.