Konjac or "Konnyaku" paste has been used for centuries to coat paper (especially in making "kamiko" paper cloth). The treated paper is called kyosei-shi strengthened paper. Once dry, the paper becomes more wind and water-resistant, improving heat retention while remaining breathable. After konjac paste is applied and dried, the coating adds texture, strength, and durability - great for book covers, stitching, dyeing, and any piece requiring strength and more flexibility.

Instructions for Use

There are various recipes for powder to water ratio. They all seem to work to one degree or another. A recipe using 5grams (1 tsp) of konjac powder to 1-quart water will strengthen the paper before the dyeing process. 

30grams (2 Tbsp) of konjac powder to 1-quart water works well for kyoseishi or momigami. If this is your first time, start with 5grams (1 tsp) of konjac powder to 2 cups of water and, if too thick, add up to two more cups of water.

Materials

Konjac powder

Room temperature water  or heat on stovetop at very low heat, stirring constantly

Spoon to mix the paste

Teaspoon, tablespoon & cup measure

Bristle paintbrush to apply paste (nix the sponge brush idea)

Washi (kozo fiber paper is great)

Plastic sheet to protect your working surface

Paste Preparation

Dissolve Konjac powder in room temperature water. Consistently stir while adding powder, a little at a time. Mix 20 minutes to prevent lumps. Occasional stirring for the next couple of hours is needed. The paste is ready when thick, smooth, and particles have dissolved. You don’t need to heat the mixture. You can dilute if the paper you use is on the delicate side.

Recipes and processes differ slightly. You will find what works best for your desired outcome. You may carefully crumple paper before application or after. Use a wide paintbrush to apply paste to both sides of paper. Fold the paper’s corners into the center and crumple the sheet into a loose ball. Place aside on plastic and proceed to another sheet, repeating process. When you have finished the first application, take each sheet, and pack it into a ball, turning, squeezing, and crumpling carefully. Open each sheet and rub it against itself, paper to paper, all over. Flatten and lightly stretch each sheet. Lay flat to dry.

If using konjac paste to pre-treat paper for dyeing, the solution may be further diluted and crumpling omitted.

Papers can be crumpled once dried many times over. 

A treatment of konjac paste gives strength to to the paper, particularly wet-strength, so when the washi goes into a dye bath, the sheets stay strong and do not break down.