403 Microfibers, a fine fiber blend, is used as a thickening additive with resin/hardener 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. Color: off-white. Please note: Delivery of West System Epoxy products within Ireland only. If a colour is out of stock, contact us directly and we can try and get it for you in the shortest delays.