Cast and calendered vinyls contrasted
By Jim Hingst
I've never been a fan of calendered films. When I entered the industry, cast vinyl ruled the marketplace. Calendered film had a bad reputation -- with good reason. These films shrunk so noticeably they left a telltale adhesive residue around an emblem -- a "ring around the collar."
As older versions of calendered vinyls aged, they became brittle and cracked. Pigmented films didn't withstand the rigors of exterior exposure. They faded, chalked or changed colors.
In the past, one manufacturer's tomato-red, calendered film frequently turned dark burgundy when used outdoors. Previously, the stiff, non-conformable calendered films were much thicker. In addition to rigidity and color fading, your father's calendered films were prone to shrinkage.
However, calendered films have changed with the times. Today, they're thinner and more flexible. Some of the newer, glossier, calendered vinyls appear nearly identical to cast films. Plus, current calendered films shrink less and cause fewer edge-lifting problems.
Improved resins, plasticizers, pigments and additives have also improved calendered films' weatherability. All these improvements spur many signshops to use more calendered vinyl than cast.
However, appearances can be deceiving. While calendered films have evolved, some performance characteristics haven't improved. That's important to remember when your name's on the sign and your reputation's on the line.
By comparing the two major classifications of flexible, signmaking vinyls -- cast and calendered -- this article will explain how vinyl films are made, outline their characteristics and offer suggestions to help you determine the right film for the situation.
Roll the film
Pressure-sensitive films typically comprise facestock, adhesive and liner paper. Polyvinyl chloride (PVC) films comprise the majority of sign materials. Polyesters, foils and reflective films are also used for sign applications, but to a much lesser extent.
PVC films include both cast and calendered materials. Because manufacturers employ different processes and raw materials to produce these films, they exhibit unique physical properties and performance characteristics.
Calendered films (which some in the sign trade still call "4-mil" vinyl) are available in various gauges. However, today, it's doubtful that any are actually 4 mils thick. As technology improved, films got thinner.
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