Did the onion skin thing for a project for my DGD a while back. the first batch was so nasty we threw it out. The 2nd batch, we put the onion skins in clean panty hose; still a little messy and we got a pretty color. We were afraid to boil too long and melt the panty hose. We needn't have worried; they didn't seem to be affected by the temperature of the water.