Whether you are an experienced dyer or a beginner, the easiest, least expensive, most available and safest mordant that
you can use is alum. It seems like a simple task to just go buy it and use it. However, you might ask yourself: should I buy
grocery store alum or aluminum sulfate? How are potassium aluminum sulfate and aluminum sulfate different from each
other? And, what is the difference between aluminum sulfate and aluminum acetate? Which is best? How much do I use?
Where do I get them? And which mordant is the best for cotton, wool, silk, hemp or abaca?