Label materials and adhesives: paper vs film, permanent vs removable

A label is three layers

A pressure-sensitive label has a face stock (the part you print on), an adhesive, and a liner (the backing paper or film it peels off). Get any one wrong and the label fails: it curls off a cold bottle, smears in a wet warehouse or tears when an applicator pulls it. Most label problems are adhesive problems, not printing problems.

Paper face stocks

Paper labels are economical and print beautifully. Uncoated paper takes pen and pencil, so it works for inventory tags and anything written on by hand. Semi-gloss and gloss coated papers are the everyday product label.

Paper does not like water. It wrinkles when damp, tears when wet and scuffs with handling. For anything in a cooler, a shower, a wet shop floor or outdoors, look at film. A coating or laminate helps paper survive light handling.

Film face stocks

Clear film gives a no-label look on glass. It needs white ink behind the design if you want colors to stay solid against a dark product.

• BOPP (polypropylene): the common choice for bottles and jars. Resists water and oils, comes in white, clear and metallic.
• Polyester (PET): tough, dimensionally stable and heat resistant. Used for equipment, rating and asset labels.
• Vinyl: flexible and conformable, good on curved or uneven surfaces and for outdoor use.

Adhesives

Two temperatures matter: the temperature when the label is applied, and the temperature it lives at afterwards. A general-purpose permanent adhesive may hold fine in a freezer if applied at room temperature, and fail if applied to a product that is already frozen. Tell us both.

• Permanent: meant to stay. Removing it usually tears the label or leaves residue. Right for product, warning and compliance labels.
• Removable: peels off cleanly for a period of time. Right for price stickers, temporary labels and promotional stickers on retail goods.
• Repositionable: can be lifted and moved while you place it, then holds.
• Freezer grade: formulated to stick when applied in cold conditions and to hold at freezer temperatures.
• High-tack or aggressive: for rough, textured or hard-to-stick plastics.

Outdoor and harsh conditions

Sunlight fades ink and breaks down some films. Water, solvents, oils and cleaning chemicals attack paper and some adhesives. Outdoor labels usually need a film face stock, a durable adhesive and a laminate or overcoat. If a label has to survive wash-downs, chemicals or a particular test, tell us the conditions and any standard it must meet.

If your label needs UL recognition, say so at the start. Commercial Printing Services is UL listed for certain label products, and the right construction has to be confirmed for your application before quoting.

How to describe your application

A good label quote starts with answers to these. Copy them into your request:

• What surface the label goes on: glass, cardboard, HDPE plastic, painted metal, powder coat, fabric.
• The shape: flat, a tight curve like a small bottle, or a compound curve.
• How it is applied: by hand, or by machine (and which applicator).
• Application temperature and service temperature.
• Exposure: water, ice, oil, chemicals, sunlight, abrasion.
• How long it has to last, and whether it ever needs to come off cleanly.
• Size, shape and quantity, plus how many versions.
• Rolls or sheets. For rolls: core size, maximum roll diameter and unwind direction.
• Any variable information: barcodes, serial numbers, lot codes.
• Regulatory needs such as UL or industry marking rules.

Test before the full run

Surfaces vary. Some plastics are low surface energy and resist adhesives. A textured lid or a powder-coated panel may need a stronger adhesive than the spec sheet suggests. When a label must work on a new surface, ask for samples of the material and adhesive and try them on the real product, in the real conditions, for long enough to know.