well, it was the amount of water in the wheat starch OR the amount I applied on the hinges.. it made the paper wet and that made it ripple...
Ugh. That's called "cockling," and it's a potential hazard with wheat pastes. It happens when the paste mixture is too watery for the artwork. You avoid it by letting your paste mixture "set" -- that is, dry a bit -- before you apply it to the artwork. Until you're familiar with the mixture, the way to find the correct setting time and avoid cockling the paper is a bit tedious:
1. Mix a batch of paste, and find a piece of scrap paper similar to or the same as your artwork.
2. prepare (tear) about a half-dozen hinges in the size you intend to use.
3. When the paste cools, brush it onto the ALL of the hinges, using as little paste as possible. Attach ONLY ONE hinge to the scrap paper, blot and weight as per the instructions.
4. As it cools, the paste will continue to thicken, so attach the rest of the pasted hinges in two-minute intervals, marking each one so you know how long the glue has set. Blot, weight, and let dry.
5. After they've tried, check all the hinges. The ones with the smallest amount of set time, the wettest, will probably have cockled the paper. The ones with the longest set time, the driest, will probably have the weakest bond. Look for hinge that has achieved the strongest bond without cockling -- that's the proper amount of setting time to use.
After you've mounted a few pieces, you'll develop a "feel" for the mixture and set times.
saL wrote: also, seeing it's so "fibery", Im quite skeptic about how easy it is to take it off if needed one day...
The fibers run one direction, which allows you to "shear" them off by peeling them down after re-activating the paste -- in theory, anyway. I've never personally removed hinges, nor would I recommend trying it unless you're selling the artwork. In any other case, just leave the old hinges and mount new ones on top of 'em.
Keep in mind that your hinges should be the weakest link in your mounting system; you always want them to tear before your artwork does. That's one of the reasons why mulberry hinges are so "fibery;" it's also one of the reasons why I'm a little skeptical of the abaca tape, which seems to be designed for photopaper applications and touts its great strength and strong adhesive.
also, I was wondering if it's necessary to strain the paste?...
I wonder about this myself. I've done it both ways, and frankly haven't noticed any difference when I don't strain.