I hope someone can shed some light on this for me....

I did some RI string work for the first time today. I used white and it worked great. The consistency was fine and it looks decent for my first try. But they I did some in red, and the red had some shrinkage problems. I made the "swags" and after I had attacked them at the top, the "swags" shrunk... and ended up as lines instead of being "u" shaped. I think the RI was the same consistency for both.. it started out working fine for both colors.

Any idea why this might have happened so I know what to do to avoid it next time? Could it have been the addition of the red coloring that made it more "elastic?"

thanks in advance!