mylar corners


SGF, Supreme Grumble Framer
Feb 28, 2002
Vancouver, B.C., Canada
Does anyone know a source for the type of mylar corner that is cut down so that only V edges (not the whole triangel)holds the paper in place?

Is this question clear as mud?


If you have the full-triangle style, you can simply trim away the center of the triangle with a razor blade.

Slip a scrap of matboard into the pocket before you do it, or else you'll cut through the whole thing.

And you can also make your own corner pockets from clear film scraps. I like to fold them with flaps that go through the mount board & are secured on back -- no adhesive on the art side of the board.
Most of the pre-made "mylar" corners are polypropylene. Is that okay with everybody?
The ones from Lineco (United # U4725 "Infinity Archival Mylar Framers Corners") say they are made from "crystal clear Mylar."

They wouldn't lie to me, now would they?

No, I don't think they would. The ones from Lineco are mylar. But the ones I have from L-J (the spiffy "maxi-view" ones) and from M&M are polypropylene. I'm pretty sure that's fine, but I need just a little bit of reassurance.
Ron, polypropylene is just fine. ANSI photographic enclosures are made from them. Not quite as clear as Mylar, but archivally sound.

Thank you, Rebecca.

Not sure what the big deal is with Mylar's clarity with respect to corner pockets. Most of my customers prefer not to see them at all once the art in matted. :D
Jim's technique with these was a great thing to learn on my trip over to the US, since then we have used them on at least 100 jobs! Thanks Jim!
Originally posted by Lance E:
...Thanks Jim!
Thanks, Lance. I'm glad you're able to put that idea to use.

Ron, it might be helpful to know that polyflute (Coroplast for those from out of town) is short for 'fluted polypropylene'. I understand the translucent 'archival' grade is made from un-recycled polypropylene without additives such as UV inhibitors and colorants.

Like so many of the things we use in framing, it's OK if it's clean, but not if it's full of bad stuff, like acid, or migrating chemicals, etc.

For example, cotton mats are considered to be very good, but cotton diapers 'full of bad stuff' from baby would not good inside a frame. Wash them first.
I've seen 3" mylar corners and have considered using them to mount large photographs, up to 24"x36". Does anyone have any experience using these large corners for large photos?
the ones we have are 2 15/16" ok, ok, 3" :rolleyes: i dont see how there would be any problem with pillowing as the piece is also being held in place by so much of the mat and then the pressure of the fitting.