There was a time in my life when I folded passionately, every day. Animals, human figures, insects, you name it.

But I got a little discouraged,because I was trying very hard to fill up some shelves in my home with my work for display. Everything went fine for a while, but then it happened. My models on my shelf began to experience this phenomenon of losing their CRISPNESS. They began to SAG and flatten out, until they were no longer fit for display. Hundred of hours of folding shot to H***! Some of them were very intricate, and I had no desire to try to repeat them.

I racked my brain for a solution to the problem. I finally figured that the figures needed to be coated with something to keep them crisp. So I tried brushing them with "Puzzle coat" That worked for a little while, but then they began to sag again.
Well, I am at a loss. Can anybody here tell me the secret to keeping my models crisp and how to prevent the dreaded SAG?

Any help would be appreciated.

You can look into the Wet Folding technique, that might be a good option for keeping your models in crisp display condition and it holds up for years.

Can you tell me a little more about that? It surely can't be what it sounds like! ( I soak a piece of paper in water and fold it in this soggy condition!)

You can find a write-up in my brother's book, "Bringing Origami To Life" by John Montroll on page 9 (it's published by Dover and should be in any museum shop); basically it's a technique using heavier art paper that is wet lightly with water with a mist bottle or sponge as it is being folded, then is held together with paper towel or soft twine to dry. Once it dries, it's like a firm paper sculpture. All you need is water and the paper, and it's best to experiment with what type of paper works best. What I just described is really all you need to follow - lightly wet the paper and fold your model then let it dry, and if needed re-wet the paper as you are folding.

I've seen other less reliable techniques used like baking the model in an oven or using wallpaper paste, but wet folding seems to give the best results and the models are great for display. This technique does lend itself to being best for larger models since the art paper is thicker than standard origami paper.

That makes a lot more sense. Thanks for the explanation! But I was still wondering if there is any thing besides puzzle coat that you could coat the models with that would preserve their crispness?

I think some people have also used shellac - I know that sounds a bit extreme, but I think the origami jewelry like earrings and such that some people sell have been brushed with a clear coat of that. It's probably worth experimenting with a few clear sealers to see what works best with what paper.

Hmmmmmmm. Shellac! I might just give that a try!

I've used the clear coat acrylic varnish sold in Wal-mart with some success. It takes more than one coat, but it's not very expensive.

Just a side note - I have a small origami nun folded by Akira Yoshizawa given to me in the mid 80's, I believe, and after 20 some-odd years, it still is in the same shape it was when I got it. He'd wet-folded it with no other preservation and it has been resting in New England, in an otherwise humid and musty old house with no detrimental effects. So when done correctly, simply wet folding will preserve a model as well as any other method.

Is there any difference between varnish and shelac?

Shellac is sensitive to alcohol and it will water spot. They say shellac is made from the "lac" bug. Varnish is more resistant.

Here's a full description:
Shellac is an animal product. The basic material comes from the Coccus lacca, a scale insect that feeds on certain trees in India and southern Asia. After feeding, the insect produces through its pores a gummy substance which hardens into a protective covering called lac. This lac is collected and then it is crushed, washed and dried. After further treatment, it is skillfully drawn into thin sheets of finished shellac. Many products such as phonograph records, sealing wax, fireworks, and electrical insulators and instruments have shellac in their composition. When mixed with alcohol, shellac forms ordinary varnish.

That was fantastic explanation! More than I could hope for!