Wrap yarn, cord, twine, lace, or other trims into loose skeins. Prewash and rinse fabric and other fibers by hand to remove any residue. To wash, cover the material with water; for each gallon of water, add 1 teaspoon of pH-neutral soap and 1 tablespoon of washing soda (also known as laundry detergent booster; widely available at grocery stores). Rinse.
Simmer and soak fibers in a mordant (fixative) solution to enhance the color's brightness, evenness, and light- and washfastness. Here's how: In a large pot, dissolve 1/4 cup of alum (aluminum sulfate from a garden center) plus 1 tablespoon of cream of tartar in 4 gallons of water per 1 pound of fibers. Add fibers to pot. Heat to simmer for 1 hour and then let cool; rinse.
We prepared a clean, firm work surface (a concrete patio) by laying down four sheets of white poster board. The garden provided colorful leaves, including caladium, begonia, heuchera, parsley, and violet. Experimenting with leaves and flowers of different plants creates unique transfers of their pigments.
We spread out a dish towel on the work surface, placed a leaf on the right-hand side of the fabric, and folded over the left half to sandwich the leaf between the layers of fabric. We used the hammer to tap firmly all over the leaf gradually making twin impressions on both layers of cloth.
Once the leaf images were complete, we unfolded the cloth and peeled off the spent leaf. We repeated the process, adding random impressions using different leaves to create pleasing effects, leaf by leaf. We used only green leaves to make impressions on the napkins.
Editor's Tip: Use an iron set on low to press the images and minimize their fading. Dry cleaning preserves the images best. If the fabrics must be washed, first enhance the images using fabric paint.