There is sometimes a misconception that thin stickers mean they are cheap. This may be the case in some instances, but high quality vinyl will last for years regardless of its thickness. What we like about thin (3 mil) vinyl—as long as it is high quality—is that it almost becomes one with the surface it is applied to.
This is easy with flat surfaces, but what about curved, bumpy or uneven surfaces? Thicker, stiffer vinyl will have a harder time molding itself to the surface than a thinner, more flexible material. In addition, the stiffer vinyl will want to move back to its original shape more than a flexible material. This may cause earlier peeling from the surface since there is more pressure to lift back to a flat shape.
The last thing we like about it is, thinner, more flexible vinyl will get into more nooks and crannies than a stiffer vinyl will. Imagine a slightly bumpy surface; a stiff, less flexible material may not reach all the little grooves leaving less of the glue adhered to the surface. A thinner, more flexible material will allow all of the sticker to mold to the shape of the surface creating a much stronger bond.
Bottom line, a thin sticker will get closer to becoming one with the surface it’s applied to than a thick, rigid one. Some people may prefer to work with a stiff material, but for longevity out in the elements, we'll take thin flexible, high performance vinyl all day every day.