CAST - 2mil , 2.5mil and sometimes 3mil
Thin film that is melted to a liquid and poured to make the vinyl. It costs more to produce. It does not shrink ( less that .5% ) as much.
CALENDERED - 2.5mil, 3mil, 4mil, 5mil
Thicker material that starts as warm pellets and is pressed, rolled and stretched to make the vinyl. Cheaper to produce. Cheaper to sell. The "memory" in the pellets makes it want to shrink back to it's original form. Look at old crappy sign lettering and it will have a big glue line around the edges. The calendered vinyl has shrunk away from the original glue. The maker cheaped out and use short term vinyl for a long term job.
Both have there advantages in cut vinyl.
$$$Cast - long term, harder to weed, harder to work with. You get more bubbles it you don't know how to lay it down. More expensive and worth it in it's proper use.
$Calendered - short term, easy to weed, easy to work with. Cheap
If you print digitally -
$$$$$Controltac - 3M now has a controltac that has a microscopic cross hatch patern in the glue to it making it almost impossible to lay with BUBBLES. It is very nice to work with. Controltac also comes with COMPLY. After you print your vinyl you can "wrap" it better around the plastic on a mirror and metal corners. It is magic to install. Comes in white and reflective white. $$$$$ worth every penny to an installer!!!!!!!!
Hope it helps.
