Craft : Paper Paste

Mix 1/2 cup of flour with 1 tsp alum and enough water to make a smooth, creamy paste; then add an additional 2 cupfuls of water and bring it to a boil for a minute or so, stirring constantly.  When cool, divide the paste into equal quantities for each of the two to four colors you plan to add.  poster paints are fine, acrylic colors are better.

Alternatively- 1 cup cornstarch and 3/4 tsp alum dissolved in 1 cup of water, once dissolved, add to 6 1/2 to 7 cups of just boiled water.  Do not cook further, just add the cornstarch adn alum solution to the scalding water.  Divide the paste into portions for individual coloring and add about 1 tbs of pain to each cup of paste.

Use on smooth, hard finished or glazed paper over which you run a damp sponge. Once the project is dry, run  a warm iron over the paper.

This is called paste paper and was once used largely to decorate book end pages- it's different from marbling, which was also used for book end pages.  There are examples here.  It's essentially finger paint for grown ups. Recipe is from Early American Life, December 1978, the author of the article says he got them from from Rosamond B. Loring and Henry Morris.

There's a really good tutorial here.