Best fabric dye for cotton? Polyester?

Thanks everyone!

whoops! Ninja’d by C3

Yes, just refreshing, not trying to make any changes in the pattern etc.

More questions:

The directions I’ve seen in the past always say to wet the fabric first. This is counterintitive. It would seem that the fabric sucking in the dye bath would dye more deeply/completely if you start with the fabric dry. Can anyone explain why wetting the fabric first is a good idea?

Am I correct in thinking that I need to wash the clothes first if they have been dried with softener sheets?