Hi Sammy
Glad that was useful - I found the document you mentioned and it does look pretty good (although a bit complicated). I was going to suggest a humidity chamber to you, so here are my instructions, hopefully they won't confuse the issue and will correlate with what you have already read!!
You can build one out of a big sheet of plastic, with a frame inside to hold it up off your object...make sure the chamber is a fair bit bigger than your document will be when it unrolls, and put rolled up damp towels or teatowels around the edges of the inside of the chamber (wet the towels then wring them out so no more water comes out).
Put your document in, making sure it doesn't touch the damp towels. Seal up the end of the chamber and wait a while - hopefully you will see the paper start to relax within an hour or so.
Wait until it feels limp to the touch - it may not unroll completely in the chamber - this may take several hours, depending on the paper. When you think it feels limp, take it out of the chamber very carefully, supporting it on a piece of card or something similar, and transfer it to your press. This can be a sandwich of several sheets of very good artists paper or blotting paper, with flat tea towels or towels on top, and a heavy, flat board on top, with some weights on that. If you don't have a heavy flat board, you can use a baking tray if it's big enough.
Cheers
Prue
