I have a huge bag of polyester fiberfill that I want to use for making trees. The fiberfill is white and I would like to make it black or at least a very dark grey or dark brown before using it. I thought of using RIT dye but is says it is for cotton and it also appears to be a really messy drawn out process. Any other suggestions?
I agree that using a rattle can would be the best solution for colouring non-dyeable material , but it might be more efficient (and more economical) to install the polyfibre on the tree armature, before applying the paint.
It’s not a how-to, but there are lots of photos of tree construction using polyfibre on natural armatures to be found HERE.
I use a product from Woodland Scenics for making trees. It’s a fibrous material that gives a realistic appearance and comes in different colors. Below is a link and picture to one of the colors, olive green.
Sometimes what you have in your wishful thinking doesn’t always work. I would highly suggest you go check out Luke Towan’s videos on making trees. How I got my inspiration on trees.