I've copied this from the 19th Century board, all suggestions welcome.

Excellent report Lemmey. I see you're using the big moss green fleece (from Amazon?) as a playing mat, I bought two and am currently conducting an experiment. I place a high emphasis on the aesthetic appearnce of the table, its a personal thing but the problem hitherto has been that big purpose built boards take forever to build and are expensive, so I need an alternative. The plan is to buy one of those HUGE sheets of poystyrene insulation (8x6 I think) and use it as the base, then construct hills and so forth from sheets of thinner foam or poly, tack with UHU POR (and I do mean just tack) then lay fleece over contoured table, secure with LONG dressmaking pins (about 2") then spray with a dilute solution of ... and this is the problem, what? I need something to stiffen it slightly which will be completely washable afterwards in a normal washing machine. When wet, tamp into the contours, when dry mask and lightly apply with a sponge or small compressor, yellow, beige, different greens etc to look like fields, villages, woods etc. Roads can be damped and pressed then lightly painted, all paints washable (children's poster from early learnng centre). I reckon on doing a complete board, start to finish, in a dry weekend. Problem is what to use as the stiffener (no, not Playboy!), PVA probably wouldn't wash out completely, I did think of sugar or syrup in water, any ideas?

The non-waterproof pva should wash out, but might take a few washes given the large surface area. I think I'd give the sugar route a miss personally.

OK, where would I look for non waterproof PVA, will it say 'non waterproof' ?
Thanks.

Starch springs to mind. It seems to be mainly sold as sprays, but Amazon sell powdered starch.

Any DIY store will sell them. Wood working glue comes in a green bottle for the non-waterproof, blue for waterproof. However these tend to be quite expensive. Check out the building section of somewhere like B&Q and you can buy much larger tubs of glue for a lot less money. Hope this helps?