Adaptable
Procion MX Reactive Dyes dye plant based fibers like bamboo, cotton, linen, ramie, hemp, jute, paper, wood, basket reed, even silk, at room temperature. With a different procedure these dyes can be used on protein fibers (wool). They can also be mixed if you are trying to match a colour, and they are transparent, so think back to your colour wheels from primary school; blue nappy + red dye = purple nappy...

Effective
Procion MX Reactive Dyes have excellent wash and light fastness. They are fiber reactive dyes - which means that they actually change the color of the fiber, as opposed to staining or sitting on top of the fiber. When used correctly, they are permanent, colorfast and washable. That's a good thing on your fabric, but think hands, carpet, passing toddlers - I recommend gloves for your hands, newspaper over any nice workspace, & wait till the kids are in bed!!

Economical
This concentrated dye, which you add to tap water, gives you the most brilliant color of all dyes. Approx: 18g of dye can dye 2 metres of hemp. 28g can dye 3 - 5 metres of fabric, or about 6 - 9 T-shirts. 58g of dye will dye 13m of cotton muslin, or 12 T-Shirts.
See "instructions for dyeing" for more details.

Safe
Procion MX Reactive Dyes are considered nontoxic when used properly. Common sense should be used when handling any dye or chemical. Prolonged inhalation of dye powder can cause an allergic reaction in some people. Keep out of eyes and mouth and always supervise children carefully. Keep dyes in a closed container in a cool, dry place and they will remain stable for several years (once they are exposed to moisture they begin to degrade).

More
Procion MX Reactive Dyes come as a powder to which you add water. Soda Ash is the fixative used for these dyes.
You can purchase Soda Ash in bulk amounts from pool supply stores, where it is known by it's chemical name of "Sodium Carbonate" (NOT sodium bi-carbonate, this is weaker for dyeing purposes).