I've been following this thread carefully, and gratefully, as I'm planning to make a copy of an old green glass longbow. I found some "Dark Sage" green linen that is a good color. I like the idea of the linen, both because, as noted, it will absorb the epoxy, but also because linen is an old fabric and one that has been used in bow making, as backing for selfbows, historically, so it "feels" right for the reproduction older style bows I do. Thanks to all who contributed.