A customer brought me a large valuable print. Whoever framed it before me did a good job archivally, taping all around for a good seal. Unfortunately after several years the matt has rippled slightly and it bugs my customer. I have taken it apart and put a piece of gatorboard in and weighted the back as I re pointed it. This took care of a lot of the issue but there is still a slight wave. Has anyone developed a way to put a pad or spacer in the middle to create a greater pressure there? When I use my hand in that way the wave disappears.

Thanks so much.
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MGF, Master Grumble Framer
Your description of "taping all around for a good seal" has me thinking.
Was the print hinged to the backer, to the mat, or taped all around to the backer or mat?

Is the problem the mat rippling, or the print rippling, or both?


SPFG, Supreme Picture Framing God
🙄 "Taping all round". I also hope that wasn't instead of hinging.....

Fact is, even if it was hinged properly, some papers will go wavy. You can often press out the waves by sandwiching
it between two sheets of matboard and putting it in the vac press for a minute or so. The heat/vacuum will draw a
small amount of moisture from the matboard and humidify and relax the paper. But there is some peril to this. It only
works on shallow waves and waves rather than bumps. And not on extreme waves.

Don't do it on anything you can't replace. 🤔

On method I have used with some success is to cut a piece of matboard slightly bigger than the mat window and tape it
in register to the window to the undermount. The trick is to snip about an inch off the corners. This makes it apply
a pressure along the edge of the window evenly. It will reduce the waves, it may or may not fix them completely.
On bigger prints you can use a thicker foamboard.


Looks like the matt has a wave. By taping all around the previous framer taped the glass, matt, art, and backing to keep out bugs et al.

Prospero that is an interesting approach I was hoping to avoid cutting apart the sandwich.


SPFG, Supreme Picture Framing God
You mean you haven't had a peek inside? What lies within could be the cause of the whole issue.

Taping the sandwich is generally a good thing. I always do it, but in such a way as to avoid any tape
going on the mat. It goes glass/bookmat/backing board. The tape wraps around the glass and backboard
and the mat is unrestricted.


SGF, Supreme Grumble Framer
If the matt was jammed into the frame too tightly that could also be the cause of the trouble in which case trimming off a millimetre or so will solve the problem. Snag is that even if you manage to flatten it there is still a good chance the ripples will come back over a few weeks.

Definitely dismantle the whole package to see what lies within but, for my money, replacing the matt would be the best option.


Forum Support Team Angry_Badger
Staff member
It's time...
It's past time.

The downside of taping the frame package is that the tape may not allow the mat to expand or contract freely with changes in the environment. Being too tight in the frame as artfolio mentioned is one cause of cockling, but restricting the mat in any way can have the same results. If you are going to tape the package, the most dimensionally stable element, normally the glazing, should be the largest with all more active elements, mat and mount, slightly smaller. That said, you still risk cockling when environmental conditions are right.

The mat will probably need to be replaced. Once it has deformed and then set in the new shape, it is difficult to get it to revert to the original flatness. You might try the heated vacuum press as Peter mentioned, but I would be inclined to replace the matting.
Another reason to take it apart is to see what's going on inside the mat/mount package. Cockling is often an indication of a spike in humidity at some point in the past and with moisture comes other issues that should be looked into and addressed if needs be.
Ideally, works on paper should be removed from the frames and inspected on a regular basis, and 15 years is not the preferred interval. More like every 3-5 years depending on the environment.

The efficacy of taping the frame package is debatable. It does make for less work in the fitting since loose debris in the frame can't transfer to the frame package, but the presence of pressure sensitive tape, and the question of not what you seal out, but what you seal in still exist. Even sealed frame technology has been challenged for claims of long term protection.


WOW Framer
Could you share a photo of the mat?


SPFG, Supreme Picture Framing God
I'm not a gambling man, but if I was I would bet my back teeth that the print was attached to the mat and
taped into place all around. The only way to fix this properly is to tear the whole thing down. 🙂

Greg Fremstad

MGF, Master Grumble Framer
Applying more pressure around the edges of the mat or art will prevent them from expanding/contracting with changes in humidity. The mat will expand/contract at a different rate than the art and the backing. More pressure with points will make this all worse. Tape sealing the glass-art-backing package will help prevent changes in humidity inside the package. Read the free article on the frametek web page titled "stop the dust pump" also the one titled "What makes art buckle in a frame"


SPFG, Supreme Picture Framing God
The way I do it imparts only a tiny amount of pressure. Not enough to restrict the paper.
Very often when you see gaps it's the back that is bowing out and biasing it toward the
glass will mitigate this. Some backing boards have a natural curve and it's a good idea to
look for this and put the convex side inwards.