Silk Painting How to

Using Dye Thickener

How to Use Dye Thickner

Sodium Alginate is a pure type of dried, ground kelp (seaweed) - it's commonly used to thicken food. It is the most economical thickener for Dyes of all types and it works as a thickener for other liquids as well. Use whenever you want to use dyes more like a paint. You can then brush the dyes on and they will stay put. Also use for stamping, stenciling or silk screening the dyes. You can also add a pinch to your dye mix for tie-dye to make the dye stay put rather than bleeding through the fabric and also for crisper lines. 

Two grades are sold:

  • High viscosity (HV) for cotton.
  • Low viscosity (LV) for silk. Low viscosity (LV) allows you to draw finer lines.

To dissolve:

Sprinkle a very small amount (1/8 to 1/4 teaspoon) of the thickener into a glass or jar of cool water or liquid dye slowly, mixing continuously to avoid clumps. A small stainless steel whisk or fork works well. Allow to sit for an hour or so, as it will continue to thicken for several hours.

Cover and refrigerate to store. Don't over-thicken, thinner is better.

It is sometimes difficult to wash out of steamed silk.

 Using Sodium Alginate as a Resist on a Scarf

  • Mix sodium alginate according to directions on the package a day before painting so it will thicken.
  • Choose the silk fabric or a garment you wish to paint; you can leave the silk white (or its original color), or paint light shades of dye on it, overall, or leaving some white spaces.
  • Crunch a plastic bag into a ball and form a “handle” with part of it, securing with tape or string; it will resemble a plastic flower bouquet with a stem.
  • Dip crumpled plastic into the sodium alginate, then dabble it all over the silk, creating whatever pattern you choose; the plastic produces multiple edges and the sodium alginate acts as an excellent non-line resist. Or, brush on the sodium alginate.
  • While sodium alginate is still wet and you can see it on your silk (sodium alginate dries clear and difficult to see), apply dyes around the sodium alginate in your own way (brush, sponge, spray, drip), then use salt crystals to add texture to the wet dyes on the silk.
  • Let the entire piece dry completely, then dabble more sodium alginate over areas of color and/or texture you like best on your silk.
  • For a second time, while the sodium alginate is still wet and protecting those areas, apply more dyes around the sodium alginate, and more salt on the wet dyes, to create your own layered, textured patterns on the silk.

(Information above drawn from instructional notes by Becky Kyhl, Iowa, 2012)


The brown spots (slightly softened by the surrounding color as it went on) are 50/50 dye plus Pro-Chemical Print Paste (thickener), by Suzanne Punch


The yellow and the purple areas are thickened color, as described above. They remain intact while surrounded by other painted colors. When painting over areas of thickened dye, the wash will partially obscure thickened dye areas. By Suzanne Punch