Retroreflective sheeting materials, more commonly referred to as just ‘reflectives’, are excellent and specialized materials for asset identification number/letter labels, and safety, notice, or even informational signs. Reflective materials are often specified by utility service companies because they not only offer excellent durability, but more-so because they offer nighttime visibility and conspicuity when illuminated by an external light source such as nearby area lighting, vehicle headlamps, or a flashlight.
But with all the reflective material choices available, understanding their differences and selecting the one that best suits your application is confusing and difficult. Here are the essentials you need to know to choose high-quality reflective materials that deliver the best performance and value for your sign or label applications.
Grade… not all reflective materials are of the same quality
Reflective sheetings are manufactured for different markets. On the low end are graphics grade reflectives used for novelty stickers, hobby crafts, and decoration. The appearance, quality, and performance of these types of reflectives are not controlled under industrial standards, they use lower quality adhesives, and are not outdoor durable. This grade of reflectives is not suitable for commercial applications, though it is unlikely that a conscientious print supplier would supply this grade to a buyer under the knowledge that it was for a commercial application.
The next highest quality level of reflective sheetings are usually referred to as utility grade or sometimes commercial grade. Note that ‘utility grade’ is not meant to imply use by utility services; but rather as being commercially usable, though inferior. While the quality and performance of these reflective materials may be specified, they are not intended for safety or critical application performance. The visual appearance of these reflectives may look the same as reflective sheetings of similar construction and lens type that are engineered for critical safety applications, but their durability is lesser and they provide lower levels of reflective intensity. The outdoor durability of most utility grade reflectives is 3-5 years.
Many ‘local’ print shops that don’t specialize in safety labels and signage often quote and supply utility grade reflectives due to cost considerations, price competitive positioning, and easy sourcing availability from their same suppliers of other graphics application films they commonly use. As well, they simply may not realize the performance inequality between these reflectives and those used for safety or other critical applications.
Traffic grade reflective sheetings are the types required for highway signs, and for good reason. They are the most durable and brightest of reflectives. And while companies such as 3M or Avery Dennison who manufacture label films for graphics applications are also the largest manufacturers of traffic grade reflectives, their graphics label divisions and reflective traffic materials divisions are separate. Unless print suppliers are specialized in safety (or traffic) signage, many don’t understand the different quality/grade and sourcing of these materials. The warranted reflectivity of traffic grade reflective sheetings is 7-12 years, dependent upon lens type and construction; and because there is no minimum reflective performance required in the utility industry, all will provide more than adequate performance for 10-15 years.
ASTM D4956 is the standard by which all retroreflective sheeting materials for traffic signs are specified, and this standard is referenced as part of Federal Highway Administration specifications where reflective materials are required. ASTM D4956 categorizes all retroreflective materials by lens type and states all required performance requirements — including color, retroreflective performance, adhesion, and durability. But while the utility industry is not required by relevant codes or regulations to use reflective materials for signs and labels having any specific quality or demonstrating any specific performance, it makes sense for you to use only traffic grade reflectives and to specify your reflective materials by Type under ASTM D4956. This way you assure the use of traffic sign quality materials, without having to determine performance specifications or include additional language about requirements.
Traffic grade reflectives are categorized by Type under ASTM D4956. While there are many available from Type I to Type XI, only a few of these Types are necessary to meet the needs of utility industry applications.
Best Types for asset identification number/letter labels, safety labels, and safety signs used in electrical utility applications
Type I is referred to as Engineer Grade, and utilizes tiny glass bead lenses in its construction. It is the least expensive reflective of the Types, and provides excellent cost/performance value.
Type III is referred to as High Intense, and also utilizes glass bead lens construction. Type III is about 3 times as bright as Type I, but has a distinctive honeycomb pattern appearance on its face. Type III has been or is being obsoleted by many manufacturers in favor of other Types, with only a few still manufacturing it. Type III is also about twice the cost of Engineer Grade.
Type IV is referred to as High Intense Prismatic, and utilizes cube-corner micro-prismatic lenses in its construction. Like Type III it has a distinctive honeycomb pattern, but is about 5 times as bright as Type I. This type also performs well at wide viewing angles. Type IV is slightly less costly than Type III.
With no minimum reflectivity performance required in the utility industry, the choice between reflectives really boils down to cost, and preference towards appearance, tactile feel and handling, and reflective intensity performance.
The other Types
The higher numbered Types often cause confusion in the mistaken belief that higher Type implies relative performance. This is not necessarily so. Types V thru XI simply provide different and specialized performance characteristics such as long-distance reflectivity at narrow viewing angles, extreme wide angle reflectivity, or flexibility for use as roll-up signs or on rebound-able devices such as traffic cones. These are performance characteristics that may be necessary for certain highway applications, but that are not necessary for utility asset ID markers and safety signs.
The Electromark Advantage
Electromark exclusively uses traffic grade reflectives for our reflective products, and provides Types I, III, IV as standard offerings. Electromark’s Type III reflective is available with low-temp adhesive. In addition, Electromark only uses the reflective sheeting manufacturers’ recommended and warranted inks, and uses the necessary translucent inks so that the printed colors also exhibit nighttime reflectivity and color as does the un-printed background material. Electromark can also supply any of the ‘higher’ reflective types when specified.