Calcium carbonate is also referred to as chalk. This dense, white powdery mineral is a common addition to the madder dye bath to deepen shades and is one of the principle minerals that create hard water. It may also be used with weld extract to bring out the bright, rich yellow shades. It is also used as a post-bath for mordanting cellulose fibers with aluminum acetate.
Calcium hydroxide is used to make an indigo or woad vat more alkaline. It is a fine white powder and is also known as pickling lime, hydrated lime or, in Mexican markets, cal. Calcium hydroxide is used in indigo vats, which we go into detail about here. It is a mild alkali and easier to use than lye or caustic soda. We provide a food grade quality calcium hydroxide. Please wear a mask when using it as it is very fine and can be an irritating dust. Calcium hydroxide can also be used when creating an indigo stock solution (also … Read more
YOU ASKED: May I ask what you mean by calcium carbonate? I read in your description of “calcium carbonate” you compare it to chalk. This confuses me because chalk is caso4•(H2O) while calcium carbonate is caco3. KATHY ANSWERED: What we call “chalk” in the US is Calcium Carbonate – CaC03, a powdery white material. The formula that you reference is Calcium Sulfate and it may also be called “chalk” but in the US, we commonly refer to it as “gypsum”. Calcium carbonate is used to mark soccer fields, as a dietary calcium supplement, an ingredient in antacids, and building materials! … Read more
We get mordant questions all the time at Botanical Colors so why not create Mordant Monday??? Got mordanting questions? Email [email protected] YOU ASKED: I’m confused. Your directions for mordanting with aluminum acetate say to mordant, place fibers in dye pot, then . . . do the calcium carbonate bath then dye – what is the correct order? “Remove, rinse lightly and proceed to dyeing. Calcium carbonate can shift dye colors due to its higher pH, so we like to rinse it prior to use.” KATHY ANSWERED: You mordant with aluminum acetate, and when it is done, remove from the aluminum … Read more
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