Although the consumer never sees it, the liner is a critical component of any pressure sensitive label. A label liner, also known as “carrier” or “backing” or “release liner”, serves a very important purpose: carrying the die-cut labels to applicator and releasing the adhesive-backed label onto the product. The diagram below shows how diecut labels are released from the liner.
Why are there so many Liners? Just like adhesives, each type of liner was engineered to meet specific performance criteria. Here are some of the quality and performance criteria used to judge a pressure sensitive label liner:
Liner Performance Criteria
Die-cutting: High speed diecut and stripping
Cost: Relative cost of the liner material
Strength: Liner web strength and durability
Layflat: Resistance to curling after sheeting
Dust: Absence of loose particulates
Types of Liner
SCK
Semi-calendered Kraft material. Low cost, all around liner for paper materials. Very good diecutting and stripping, poor layflat. Moderate particulate levels.
PK
Poly-coated Kraft liner has a poly layer that improves die-cutting and strengthens the liner. Is credited with lower incidence of web-breaks due to deep die-cuts. Higher cost than SCK, slightly lower dust particulate. Does not sheet well.
LF
Lay flat liners have excellent stability and resistance to curl for sheeted applications. Higher cost than SCK liners. Moderate particulate levels.
PET (Poly)
Polyester film liner – durable and good for high speed die-cutting and stripping. Poor sheeting characteristics. Very low particulate. More expensive than paper liners.
BG (Glassine)
Bleached Glassine liner – low cost. For low to medium speed dispensing, not recommended for sheeting.
As you can see, no one liner can do everything. Much like facestock materials, liners must be selected based on the specific label requirements. Sheeted labels require liners designed with lay flat in mind. For roll labels, the applicating equipment will usually drive liner selection. With a robust, modern label applicator a standard SCK or BG liner will work well for the majority of labels. For clean room (zero particulate) and pharmaceutical (high speed application) a polyester liner is often the only option. Ask your Custom Label representative to help you specify the correct liner for your custom labels!
Conventional wisdom indicates that during recessionary periods, new businesses appear at a higher rate. Terminated employees strike out on their own, determined to take control of their future. For many an entrepreneur, they are in un-chartered waters. Custom Label works daily with these heroes of industry. We are often contacted with the generic question “I’ve got a bottle and I need to put a label on it!”. Just this week I was contacted by a start-up, and the owner said “my bottler told me I need a pressure-sensitive label, whatever that is!” In this blog entry I will answer that question, and help you understand how we ended up with this product called “pressure-sensitive”.
With Earth Day nearly at an end, I started wondering. Who declared the first Earth Day, and why? Did they realize how important environmental awareness would become, and at the same time how polarizing an issue?
responsible for stabilizing its own population. It can be done.” Quite a different spin on environmentalism! Even more ironic, one popular environmental concern cited “imminent cooling” of the earth’s surface and “glaciation” as a significant threat to our environment! A downward temperature trend was observed during the 30 year period preceding 1970 which alarmed some scientists, and led to the popular fear of “Global Cooling”.
Whether our planet is cooling or heating, one thing is certain. We should all do our best to use earth’s resources wisely and reduce waste. Custom Label is ready to help you find packaging materials that are environmentally friendly. Our Digital Label press is a perfect example. Digital printing has significantly lower material waste than traditional flexography, letterpress, or rotogravure. By running an order digitally we avoid the need to “set-up” the press while running waste stock through the press. Selecting an eco-friendly label stock is also a way to green up your package. We offer a range of facestocks that have higher post-consumer-waste content. There are also bio-degradable and compostable materials that Custom Label can propose for your labels. We even have renewable materials, such as tree-free bamboo papers, where the source plant can be replenished faster than the consumption rate. Give your representative a call, Custom Label would welcome the opportunity to help you create a more eco-friendly package!