Available fillers and additives give you the abiltiy to customize WEST SYSTEM 105 Epoxy Resin for your specific application.403 Microfibers Adhesive Fillers, a fine fiber blend, is used as a thickening additive with WEST SYSTEM Epoxy to create a multi-purpose adhesive, especially for bonding wood. Epoxy thickened with microfibers has good gap-filling qualities while retaining excellent wetting/penetrating capability. Off-white. 20 pounds. For the suitability of fillers for specific applications, see theFiller Selection Chart