Guys, for anyone still interested in this topic try this....
1. get a tea bag and empty the tea out
2. cutdown the side so you 'butterfly' the tea bag so to speak
3. get some good quality sticky tape and tape over one side
4. The other side is porous so it can be coloured any shade you like
I have medallion sheeting on my tying bench right in front of me right now... alongside my teabag alternative... if ANYONE can tell the difference I'd be most surprised. note, that the other side of the teabag, i.e that side without the tape is porous so can be coloured any shade you like.
Same technique also works for caddis wings btw..... just fold the tape tea bag and if makes an amazingly resilient caddis wing.
Cheers,
Jon