Here are a few considerations when thinking about decals.
Probably the 2 most important things about decals are application and duration.
Application refers to where you want the decal to go. Will they be subjected to the sun or other weather conditions or are they indoors, where temperature, moisture, sun or physical contact are not as big an issue. Also, are they going on a smooth regular surface or one with a lot of contour changes and/or corners.
Duration refers to how long you want them to last.
Lets look at application and it’s requirements first.
Probably the toughest application for a decal is on a vehicle. They are subjected to extreme hot and cold, physical contact from washing, rain, slush and snow as well as UV from the sun which will fade the ink.
For these a good quality vinyl and laminating are a must for all but the very short term applications. A reasonably good quality vinyl will give you 5 years and the laminating will extend this and protect the ink from UV as well as scuffing from physical contact and washing. Remember that the life of the vinyl has nothing to do with the life of the ink, which is greatly affected by the sun’s UV rays. There are also longer term materials made specifically for longer term and specialized vehicle applications.
Another consideration is the contour of the application area. If it’s a smooth area then that reasonably good quality vinyl will do. If, however, you want it to go over locks, seams, rivets or some other sharp contour, you will need a highly flexible vinyl that will conform to any contour. The laminate must as well. Wrap material is probably the ultimate with this ability but there are some less expensive options. A wrap, of course, is just a huge decal, but with some very special qualities.
If the decal is going on a hard to stick to area, a Hi Tack adhesive might be required. In our experience, certain low VOC paints, which are environmentally friendly and very slick, as well as some wallpapers are like this.
Another application is applied to the inside of a window to be read from the outside. This can be on a vehicle or storefront window. These are usually printed in a mirror image, on clear vinyl and either overprinted or laminated white. The white background adds contrast so the image can be more easily read. The clear vinyl can have a permanent adhesive, but more often removable. The removable adhesive decal won’t fall off, but can be more easily removed.
The same can be produced with a static material but is not recommended when cold temperatures are expected as the static charge will not hold up in this case.
Indoor applications have less concerns. The solvent based inks will hold up to water, but certain cleaning products may harm them. In this case laminating is still recommended. The same is true of decals that will be subjected to direct sun.
All of the above assumes that you want them to last for years. If all you need is a few months, as with events etc., then you can save a bit by not laminating and going with a less expensive ‘calendared’ vinyl. Although not a lot less expensive, it will save a few bucks. Also, if you need to remove the decal after it’s usefulness, a removable adhesive is recommended.
These are a few considerations to get you thinking about what it is that your requirements are.