Quick Guide to ASTM D-4956 Sign Sheeting Types and Adhesive Backing Classes –
There are nine types and five classes of retroreflective sheeting.
Types are determined by conformance to the retro-reflectance, color, and durability requirements (as listed in the standard) and may be of any construction providing that those requirements are met. Common references for each type of retro-reflective sheeting are:
Retro Reflective Sheeting Types (ASTM D-4956) –
(Note – For comparison, candela ratings are based on a .2 observation angle/-4 entrance angle)
- Type I – Engineering Grade (Glass Bead Technology) (75 Candelas for White)
- Type II – Super engineer grade (Glass Bead Technology) (140 Candelas for White)
- Type III – High-intensity Glass Bead (Glass Bead Technology) (250 Candelas for White)
- Type IV – High-intensity Micro-Prismatic (360 Candelas for White)
- Type V – Super High Intensity Sheeting for Delineators (typically a thin metalized film – rugged and incredibly bright) (700 Candelas for White – up to 2000 Candelas for .1/-4 observation)
- Type VI – Elastomeric retroreflective sheeting without adhesive – Roll up Sign Material (160 Candelas for Pink)
- Type VII – Discontinued and Replaced by Type 8 Sheeting.
- Type VIII – Retroreflective sheeting typically manufactured as an unmetalized cube corner Micro-Prismatic retroreflective element material. (700 Candelas for White)
- Type IX – Retroreflective sheeting typically manufactured as an unmetalized cube corner Micro-Prismatic retroreflective element material. (380 Candelas for White)
- Type X – Discontinued and Replaced by Type 8 Sheeting.
- Type XI—Retroreflective sheeting typically manufactured as an unmetalized cube corner Micro-Prismatic retroreflective element material. (580 Candelas for White)
Adhesive backing classes –
- Class 1 – Pressure-sensitive adhesive (no heat or solvent) – most common
- Class 2 – Adhesive activated by heat and pressure
- Class 3 – Repositionable low-tack pressure-sensitive adhesive
- Class 4 – Low-temperature (-7°C) pressure-sensitive adhesive
- Class 5 – Non-adhesive backing (i.e. roll up signs)
Steven Cole (Economics, MBA – University of West Florida , Business & Innovation – Stanford University) 25 years of experience in the reflective safety business. Specializing in vehicle accident and rear end collision reduction through increased visibility.
