This will be my last post on Shibori for awhile because I've run out of PFD fabric and have to order some more. When I did my last batch I had an awful lot of dye left in the bucket and it seemed a shame to throw it away, so I experimented with putting in a small piece of white fabric to see it the dye was still viable after several hours. The fabric took the dye, although it was much lighter than the original batch. So I quickly sewed up two tubes of fabric to fit over the pipes, scrunched it down and put it in the dye pot for a couple of hours. When I rinsed it out, I had the nice light blue on the left. I scrunched one of the them again and put it back in for an hour or two and got the results on the right. I guess I could have done more, but as I said, I was out of fabric.
From now on, when I do a batch, I will have another batch ready to go in the now weaker dye. Maybe I'm making my dye too strong, but I was happy with that deep dark color achieved on the first dip.