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Janis Kent, FAIA Architect, CASp © July 2018. Updated February, 2020 One of the items that did not seem entirely clear to me was reflective or reflectorized signs for parking, and how do you recognize them, vs glossy or matt signs. At one point I looked for small dots in the signs but many of them seem to be faded with no added benefit that I could discern. And recently I have been seeing the signs with linear type prism bands. So what is required, what is the difference, and what are we looking for? Reflectorized signs are not self-luminescent and are dependent on an external lighting source. With natural daylight, the reflectivity is not readily apparent, so no glare, but at night time, with artificial light hitting the surface, the reflectivity becomes present. This type of reflection is called retroreflective as opposed to diffuse or mirror reflection. There are approximately 9 different grades which can be divided into the following three classes of reflectivity. Engineering Grade Reflective – Glass-beaded optics The small dots that I had originally looked for is one form of reflectorized or reflective signs. The dots are comprised of small glass beads imbedded into the top film pigment. The limitation, though, is after a period of time the dots, deteriorate and loose the quality of being reflectorized. This happens quicker when located outside rather than in parking structures. So this type of sign fabrication may only last for a few years and then after a period of time becomes just a matt sign. This is a more inexpensive sign manufacturing process but I do not believe that property owners and facility managers realize the limited life-span and the requirement of maintenance/replacement. High Intensity Reflective – Prismatic A different sign manufacturing process provides an embedded linear type banding within the film. The banding is prism-like and is what causes the reflectorization. The prisms also reflect at a wider angle so it is more noticeable and is bright when approached from an angle. This lasts longer than the glass beaded process and I have been noticing this type of sign much more often. This grade provides for about 3 times the reflectivity as Engineering Grade. Diamond Grade Reflective – Prismatic A third type is what is typically used on freeway and highway signs and is something I am also seeing more of. This also has an embedded prism type structure within the enamel in a diamond-shaped pattern, and is even more durable. The manufacturing process is more difficult for fabricators to cut, hence more expensive. But it does last longer and provides for the greatest reflectorization making it easier to read at night and even day time with sun shining on it. This grade provides for about 3 times the reflectivity as High Intensity Reflective. I would suggest not specifying the sign type of Engineering Grade Reflective with glass beads for parking signs on the exterior since they are less durable. Within a garage it should last longer but the owner should be aware that this is not a permanent sign process and over time it will deteriorate and require replacement. For that matter, none of the sign fabrication processes are permanent, but the prismatic types do last longer. And I also would suggest specifying the manufacturing process on the drawings. Be aware that your local City or County may have additional requirements that are more restrictive than the State or Federal requirements. Also, this article is an interpretation and opinion of the writer. It is meant as a summary – current original regulations should always be reviewed when making any decisions. Janis Kent, FAIA Architect, CASp © July 2018. Updated February, 2020 If you like this article and would like to see more, please consider subscribing to our mailing list »Reflectorized Parking Signs – Exactly What is That?
