A commonly asked question we get here at ComicProLine is what the difference in each "PT" we have for our comic backer boards are. To sum it up simply, the higher the "PT" the thicker and stronger the backer board will be. We have 4 different thicknesses you can purchase from us. That being 24pt, 28pt, 56pt and 60pt. The 24pt being the industry standard thickness. Our 60pt being the thickest board we have and the only one we have that is made of P.E.T material and not paper like the rest of our thicknesses. Some customers worry that the thicker boards won't fit in their bags or will be too thick to slide the comic in with the board. To that we say do not worry! We can 100% say that if it is ComicProLine bags and boards and the bag size matches the board size purchased from us, they will fit. We can not vouch for other brand bags that are not ours.