Labels have many uses: product identification, name tags, advertising, warnings, and other communication. Special types of labels called digital labels (printed through a digital printing) can also have special applications such as RFID tags, security printing, and sandwich process labels.

Attachment

Labels can be attached by:

• Pressure sensitive adhesives (also called PSA or self-stick) are applied with light pressure without activation or heat. PSA labels often have release liners which protect the adhesive and assist label handling.
• Heat activated adhesives: for example, "in-mold labeling" can be part of blow molding containers and employs heat activated adhesives. Hot melt adhesives are also used.
• Wet glue (starch, dextrin, PVA, etc) or water moistenable gummed adhesive
• Yarn or twine for tying on a label
• Rivets used to attach information plates to industrial equipment
• Shrink wrap for printed shrinkable labels placed over packages and then heated to shrink them
• Sewing for clothing, tents, mattresses, industrial sacks, etc

Adhesive types

Pressure sensitive label adhesives are commonly made from water based acrylic adhesives, with a smaller volume made using solvent based adhesives and hotmelt adhesives. The most common adhesive types are:

• Permanent - Typically not designed to be removed without tearing the stock, damaging the surface, or using solvents. The adhesion strength and speed can also be varied. For example, full adhesion can be nearly instant, or the label can be almost removable for a short period with full adhesion developing in minutes or hours (known as respositionable adhesives).

• Peelable - Adhesion is fairly strong and will not fall off in normal circumstances, but the label can be removed relatively easily without tearing the base stock or leaving adhesive behind on the old surface. The adhesive is usually strong enough to be applied again elsewhere. This type is frequently known as 'removable'. There are many different types of removable adhesives, some are almost permanent, some are almost 'ultra peelable'.

• Ultra-peelable - Designed principally for use on book covers and glass, when removed these adhesives labels do not leave any residue whatsoever. Adhesion is weak and only suitable for light duty applications. Normally these labels have very little adhesion to anything once they've been removed.