Sharing this info from Vator DTF indonesia group. There are 2 types of PET film. (via Google translate)
"A little more sharing for the type of DTF Pet Film. So from the results of the introduction of several factories, there are indeed 2 types of cold peel pet films, namely:
1. Pet Film which has a rather thick coating layer so that it can accommodate more ink with a thick setting or a high speed printer that needs faster ink absorption. The coating character will blend with the ink and when it is removed it will come off, giving an additional layer over the ink surface with an effect like a slippery wax coating. Cold Peel type, so it is removed when it is cold and a little slow because the coating will come off with the ink. An example of this Pet Film is the MTX V8 brand that Hobby Print sells.
2. Pet Film that has a coating that is a bit thin but still absorbs ink well. This Pet Film character coating when heated will separate from the ink so it is very easy to remove, very suitable for DTF screen printing for logos or very small letters. Coating does not come off with ink so that the screen printing relies on the strength of the ink itself. An example of this Pet Film is the Image Seven brand that Hobby Print sells."