קיפול יבש/רטוב
אני מצרף כאן קטע ממאמר שכתב רוברט לאנג ל - o-list על קיפול יבש/רטוב, ובו הוא מסביר כיצד משתמשים במתיל צלולוז.
However, recent years have seen the rise of the super-complex model, particularly super-complex insects (and here I use "insect" in the broader generic sense of "scuttling thing with lots of appendages" rather than its precise taxonomic definition). It is not unheard-of in such design for the legs to have as many as 100 layers of paper in them. This pretty much dictates that the paper be incredibly thin. But thin paper will completely fall apart if you dampen it, so the usual wet-folding techniques don't work very well. (2.2.5) Wet/dry folding. The idea of wet-folding is that the sizing binds the fibers of the paper so that they hold their shape when dry, and dampening weakens the paper so that it can be folded at all. But really thin paper needs no dampening to make it foldable; it's quite foldable as-is. The solution, then, is to fold the model entirely dry, then selectively dampen the parts that need curvature and shaping. (Or, in the case of bug legs, compression.) But you still need the sizing to make the paper stiff when it dries. So you dissolve some sizing in the water you use to dampen the paper. For me (and others), the preferred sizing material is methylcellulose, aka MC, aka bookbinder's paste, aka wallpaper paste. (Also aka cough syrup thickener, McDonald's "thick creamy shake" thickener-creamy-er, Hollywood alien slime...like zinc oxide, it's everywhere.) It comes as a powder that you dissolve in water. You can buy MC from art shops, where they'll sell you a teeny tiny bottle for an exorbitant sum, or from chemical supply houses where you can buy pounds of the stuff on the cheap. You dissolve the powder in water according to package directions, getting a clear liquid whose consistency should be somewhere between that of syrup and snot. Which consistency you use is a personal preference; I tend to lean toward the nasal, myself. Anyhow, after you've got some, you fold the insect (or octopus, or whatever) dry until you get to the point that it's time to do some shaping; then you use a small paintbrush to apply your solution of MC to the parts needing shaping. You can applying between layers and/or on the outside; it will soak in and when dry, leave (almost) no visible residue (depending on the paper, of course). then do your shaping and let it dry. What papers work with wet/dry folding? Almost anything that's thin. Papers I particularly like are Nepalese lokta, Thai crinkle-dyed unryu, Korean hanji, Japanese kozo papers, itajime washi, and of course, the amazingly thin and strong abaca/hemp papers from Origamido Studio. I have become fairly addicted to this technique in recent months because of the control it gives me over the final appearance of the model and its resulting rigidity. It also lets me (actually, forces me) to do the final shaping on a model over a period of days; I'll dampen and shape the body, for example, let it dry, then come back and dampen and shape the legs, let it dry, then finish with the wings. (Or whatever.) Drying can be somewhat hastened by using a hair dryer, but you have to be careful because too-quick drying can result in warping, particularly if you dry the outer layers while inner ones remain damp. I call this technique "wet/dry folding" or "MC-folding", since you're doing some of it wet, some of it dry, and of course, MC plays a major role in it. The nice thing about this technique is that you can use it with archival papers to get a very long-lived model. Methlycellulose itself (and its relatives, e.g., Carboxymethylcellulose, a slightly tougher version) are very stable and are used by archivists around the world. Provided you're using the pure stuff (wallpaper paste has additional additives), you can be assured that you're not degrading the paper's longevity by its use.