Find yourself some bags. Mine (all clean after a wash) are my hemp, cotton & calico shopping bags.
Collect together the supplies you will need (clockwise from top left): dye powder (or liquids), milk bottles to mix the dyes in & gloves to protect my hands; salt & detergent to go in the dye water; kettle (you need boiled water to mix the dye powder) & plastic crates to hold the mix.
I mixed my dyes in empty plastic milk bottles - less mess 🙂
I then wet my bags with warm water - this helps the dye take better.
Then it's outside to mix the dye, taking my wet bags with me. If you don't already have your gloves on by now it's a good idea to put them on!
Now comes the patience part! I'm wanting the dye to creep up through the fibres, so I've left half the bags hang over the edge of the plastic tub. I ended up leaving them about 30-40 minutes.
Once you've let your bags sit for the length of time you need (up to 1 hour & remember - shorter time = lighter colour; longer time = deeper) it's time to rinse. You're supposed to rinse under warm then cold water, but because I was out in the yard simply used the tap. Rinse until the water runs clear.
Then hang & admire. I haven't run my bags through a wash yet - they simply got an iron & were used the next day (with lots of comments from the shop owners who know I take my bags with me when I shop). If you do need to wash your bags though, be sure & run them through a separate wash a couple of times to remove any excess dye.
Now go do some groceries!