Alginate is a natural polysaccharide derived from brown algae. It is a hypoallergenic material initially produced for dental casting, but can be also used in art for making molds.

Alginate has a single-use nature: it can turn from a liquid state into a semi-solid state depending on the temperature. However, it can not turn back.  Alginate sets quickly (2-5 minutes) and captures fine details.

Compared to other casting materials like silicone or polyether, alginate is more affordable and is easier to use.

Alginate does not stick to anything.

Alginate is an organic material; therefore, it will shrink and deteriorate quickly after the mould is created. You can cast into your alginate mould with plaster or gypsum. Resin is not a suitable material to cast into alginate, as the moisture in the mould will prevent the resin from curing. Before casting into your mould, rinse it out under lukewarm water, as this will remove any dirt or oils from the hand that may affect the cast surface.

Alginate is biodegradable.