If you’re reading this blog in Europe – you’re probably already aware of Rosco’s Supergel range of color filters. Many lighting professionals in North America, however, aren’t aware of the brand – but thanks to myColor and our website, they’ve been seeing the name more frequently and have been calling with inquiries about this “new range of 'super' Rosco gels.” Supergel isn't new at all. In fact, it's been our most popular filter range in Europe for decades! Below we examine what makes these gels so “Super” and how, if you’re in North America, you’re probably already using them in your work.
There are, essentially, three processes for manufacturing plastic color filters: 1.) Surface Coated, 2.) Deep Dyed and 3.) Body-Colored Extrusion. While each process has its own set of advantages and disadvantages, the third process, Body-Colored Extrusion, offers some distinct benefits that the other two cannot - and Rosco Supergel is the only lighting filter manufactured this way.
The process begins with clear polycarbonate resin pellets that are melted down. Under intense pressure, and heat approaching 600°F (315°C), the molten resin is combined with the appropriate dye and then extruded into a 3 mil (.08 mm) thick, 24-inch (60 cm) wide film that is cut into the Supergel sheets and rolls for use on theatrical stages all around the world.
The body-colored polycarbonate process we use to manufacture Supergel offers three advantages over other color filters: color stability, heat resistance, and flame retardancy.
Because Supergel is body-colored, the dye is actually a part of the plastic. This means that the hue of the filter will remain constant as it fades. When it comes to surface-coated filters, the colorant is not a part of the plastic, which allows the dyes to migrate away from the heat. This process can cause the color to shift as it fades. Some blues, for example, have a tendency to shift toward green as they fade. Supergel’s body-colored process prohibits that from happening.
Supergel (L) vs. a surface-coated filter (R) - note the green color shift in the filter on the right
Rosco’s extruded polycarbonate offers two advantages over polyester films. First of all, Rosco Supergel filters are the only inherently flame retardant color filter in the world!
Reco
gnizing the global importance of safety and fire prevention, Rosco includes a fire retardant additive in our polycarbonate resin formulation to create self-extinguishing filters. Supergel has been tested according to the strictest standards in the US and Europe, and is the only filter range to have earned the demanding German B1 flame-rating. It has also obtained the French M1 and the Italian CI flame-ratings, as well as NFPA classifications.
Polycarbonate also has a higher softening point than polyester - meaning that it will maintain its shape and tensile strength in hot fixtures better. Polyester films are also stretched into their final shape and thickness. This orientation imprints a tension memory onto a polyester color filter that causes it to pucker and distort when placed on hot lights. In contrast, Supergel is extruded into its final state without any stretching – enabling the color filter to maintain its shape without puckering in high temperatures. Both of these features are particularly advantageous when using color-scrollers, where puckering and softening/drooping of the filters can cause a scroll to rattle and bind up.
As mentioned at the beginning of this article, most of our European customers are already familiar with the Rosco Supergel brand and know they can purchase Supergel from any Rosco dealer. Customers in North America will be happy to know that our Supergel filters are already inside the Roscolux swatch books they’ve got right now. Roscolux is a mixture of deep-dyed polyester filters and extruded polycarbonate Supergel filters. To see the complete list of available colors – visit the Supergel page on our website, or you can also sort through the Supergel filters in our myColor web app.
Joel Svendsen April 17, 2018 Questions?
Marketing Director: Joel's Rosco career began in Rosco's Hollywood office in 1999 – first in sales covering the Western US and the Los Angeles Film & Television market, and then as Product Manager for Rosco's Film & Television Products. Joel's knowledge about Rosco's products and how they're used in each of our different marketplaces makes him well suited for bringing the stories in Spectrum to life.