Step 1 What you'll need

As I said earlier if your paper is 140lb (300gsm) or less you will need to stretch it onto a suitable base first. Not hard to do - you don't require any fancy equipment. Just a flat wooden board, a sponge, an old towel and Gummed paper packing tape. Oh a container of water, I use the one I paint with (a large plastic fizzy drink bottle with the top sliced off.

Step 2 The Method.

Lay the towel flat over the base board you're going to stretch the paper on.

Step 3

Lay the paper onto the towel.
Tear off 4 pieces of the gummed paper tape, relative to the paper size i.e. obviously about an inch or so longer than each edge.

Step 4 the fun bit!

Soak the sponge in the water and liberally sponge both sides of the paper, doesn't realley matter how much water you use.. thearapy time
give the paper a good bath