I just read your post in projects for the design using Angelina Fibers. Here in the states we can buy the sheets of Mylar or the Angelina Fibers which is basically shredded Mylar. I have not used the fibers and after reading the process in which to use it (ironing them to melt them into a sheet) I think the sheets are easier.
I am not sure however if you use the dyed fibers if the melting process helps when wanting to use colors. Here if you use the dyed Mylar when the item is washed the dye washes out. The link I posted sells Mylar in the USA and overseas. She also has a ton of information so click on everything and read it all if you want more info on Mylar.
I believe angelina fibers are mylar that is shredded. I have not worked with the shredded type of mylar. Yes the effect of mylar is gorgeous so I am sure the shreds are also I just never thought to try them.
I have washed one of my garments using angelina at least 5 times with no colour loss....give it a try, you can get some stunning results