403 Microfibers Adhesive Filler, is a fine fiber blend.
Use it to thicken epoxy blended resin/hardener and create a multi-purpose adhesive.
It’s most popular use is for bonding wood. Epoxy thickened with microfibers has good gap-filling qualities but will still do an excellent job of wetting-out/penetrating into wood fibers.
Blended with epoxy, it will cure to an off-white color.