Author Topic: Compression waves on newly-framed posters  (Read 2650 times)

Offline Zagnut

  • Beginner
  • *
  • Posts: 12
Compression waves on newly-framed posters
« on: January 29, 2019, 02:10:15 PM »
I have three kinds of 27x40 poster frames:

1. Wood frames with the metal tabs you bend down behind the poster backing board.  Had them over 20 years.  As they're a bit delicate/flimsy, I just keep some Star Wars repros in them;
2. Plastic frames from Michael's (newest) with the metal swivel tabs behind the poster backing board; I keep new releases in these as they're easier to rotate them out.and
3. Metal frames with spring clips behind the poster backing board.  They're a pain to rotate posters.

Before mounting new posters I always place them in one of those plastic poster board bags, flat, and weighted to make them nice and flat.  Then I place them in the frames. 

After a few days in the metal frames, I notice some waves.  This is odd, as the frames have some room for the posters and aren't too small.

Here's what I have done:

1. On the wood frames I just use a nice thick piece of cardboard and there are zero waves.  This replaced the heavy wood-like board.
2. The plastic frames, which are new, have only rarely had the smallest inkling of waves.  No mods done or needed. 
3. The metal frames were originally rescued from a defunct school and the "poster" part was just printed onto the  foamboard.  When I added a poster to these, there were waves in a few of them.  When I took out the foamboard and used 2 sheets of cardboard instead, there were fewer waves and not enough room to use the spring clips.

So, in these metal frames, what can I place behind these posters to prevent/mitigate these waves?  The extra cardboard sheets have helped, but no more will fit in there.

Offline erik1925

  • Administrator
  • Post-aholic
  • *****
  • Posts: 20330
Re: Compression waves on newly-framed posters
« Reply #1 on: January 29, 2019, 03:44:07 PM »
I would use acid free 1/4" thick foam core as the backing board, over any kind of regular cardboard. Plus, reg cardboard is acidic, which you dont want pressed to the back of your poster -- especially over an extended period of time.


-Jeff

Offline jayn_j

  • Hoarder
  • ****
  • Posts: 2597
Re: Compression waves on newly-framed posters
« Reply #2 on: January 29, 2019, 03:52:01 PM »
Might read around the site a bit.  The current wisdom with the spring retainers on the metal frames is to just place clips at the top to keep the poster from sliding down, but leave the sides and bottom free of clips.  I find that over time the poster will create waves from expansion/contraction if it is clamped all around.
-Jay-

Offline Zagnut

  • Beginner
  • *
  • Posts: 12
Re: Compression waves on newly-framed posters
« Reply #3 on: January 30, 2019, 03:59:49 PM »
I seemed to have left out an important point: I keep paper between the poster and whatever's behind it, sometimes 2 sheets of it.

But the idea of just using the spring clips on the top is interesting.  I'll have to try that next time I rotate.

Offline bigmike

  • Collector
  • ***
  • Posts: 556
Re: Compression waves on newly-framed posters
« Reply #4 on: April 03, 2019, 09:06:29 PM »
Might read around the site a bit.  The current wisdom with the spring retainers on the metal frames is to just place clips at the top to keep the poster from sliding down, but leave the sides and bottom free of clips.  I find that over time the poster will create waves from expansion/contraction if it is clamped all around.

Jay is spot on. Just leave the clips on the top. Not on the sides or bottom. No more waves/ripples.
I have had this issue when using the clips on the sides as well... I have had posters now in the frames with the two clips on the top only for 5 years and no issues at all...

Offline Stefano

  • Beginner
  • *
  • Posts: 56
Re: Compression waves on newly-framed posters
« Reply #5 on: May 11, 2019, 08:58:50 PM »
Just wondering if the poster were folded or rolled?  I've had a few rolled posters framed with clips on all sides for many years and have never noticed any waves.  Wondering if I'm just lucky, or if rolled posters are just more co-operative in frames.

Offline jedgerley

  • Hoarder
  • ****
  • Posts: 2021
  • edgeslenticulars@gmail.com
    • The Poster Dungeon.
Re: Compression waves on newly-framed posters
« Reply #6 on: July 23, 2019, 01:30:37 PM »
Would a snap frame solve this problem?