Wet-folding
Wet-folding is a technique in which thick paper is slightly dampened before folding, so it can be shaped into soft curves that hold their form once dry.
It is credited to Akira Yoshizawa, who used it to give his animals rounded, lifelike bodies. The paper needs to be fairly heavy and contain sizing, a substance that makes the fibers bond again as they dry. The sheet is dampened evenly with a cloth or sponge until it is supple but not soaked, then folded and sculpted, and left to dry in shape, sometimes held with clips.
Too much water makes the paper weak and blotchy, and too little makes it crack. Test on a scrap of the same paper first, and re-dampen gently if it starts to dry before you finish. Wet-folding is used for display models rather than everyday folding; thin kami and printer paper are not suitable.