Stickers and Decals

A Decal is any kind of tag attached with adhesive to something so as to identify the object or its contents. Decals come in many forms and can be differentiated by the type of base material, called stock, that they are printed on, and by the adhesive type that they use. The most common type is made with a paper stock and a colloquial term for it is a sticker. Decals have many uses, from product identification to name tags.

Adhesive Type Decals

Permanent - Typically not designed to be removed without tearing the stock or using solvents. The adhesion strength and speed can also be varied. For example, full adhesion can be nearly instant, or the decal or sticker can be almost removable for a short period with full adhesion developing in minutes or hours. This is considered the most popular and cheapest option by many self adhesive paper manufacturers.
Removable - Adhesion is fairly strong and will not fall off in normal circumstances, but the decal or sticker 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.
Semi-permanent - aka repositionable - Adhesion strengthens fully after application (approx 48-72 hours), allowing the decal or sticker to be removed easily if placed incorrectly and still be a permanent decal.
Freezer permanent- special type of removable adhesive that remains fully permanent under certain temperatures. This is useful for labeling objects that are to be stored in a freezer for any length of time.
Tamper evident- special types of label-stocks that comes in different guises; example 1 is a weak material, that breaks into tiny pieces (Frangible) or example 2 could be a material that uses a two-stage adhesive that will reveal any attempt of removal or replacement.

Decal Uses

Stickers and decals are very widely used when an object requires identification with a word or idea. Brand stickers may be attached to products to identify those products as coming from a certain company. They may also be used to describe characteristics of the products that would not be obvious from simple examination. They are frequently distributed as part of promotional, advertising, and political campaigns; for example, in many voting districts in the U.S., decals indicating an individual has voted are given to each voter as they leave the polling place, largely as a reminder to others to vote. Other methods of underground forms of voting for your favorite graffiti artists' current productions are by an open form of appreciation such as clapping while passing such a sticker (a smile and a kind reminder to a fellow appreciator throughout the day is commonplace as well).

Stickers and decals placed on automobiles, called bumper stickers, are often used by individuals as a way of demonstrating support for political or ideological causes. Identification of vehicle registration and last service details are two examples of stickers on the inside of most car windscreens. The term "window sticker" is generally used for vinyl labels which are stuck to the inside of a vehicle's window, as opposed to water-resistant stickers that are stuck to the outside of a vehicle.

If one wants to remove a bumper sticker, and this decal is not one of the easy-to-remove variety, then a penetrating adhesive remover or the use of a heat-gun can be used.