Not always do you need dyes and other hard to find products to change the look of your old T-Shirt. Many a times you can also do it with very simple products found at home. I tried bleaching one of my old T-Shirts with regular fabric bleach and the results turned out lovely! Here is an instructable showing my process.
Step 1: You Will Need
An old T-shirt ( any color but white)
Bleach (I used liquid chlorine bleach)
And some plastic squares
Step 2: Fold It!
Start by folding your shirt in an accordion fold vertically. The smaller the folds the smaller the shapes on the final design will be.
Now turn the shirt horizontally and then fold in the same manner. You will should have small squares in the end.
Step 3: Wrap It
Once it is properly folded, place the plastic squares on the exposed edges and secure the whole T-shirt with the help of some rubber bands.
Step 4: Bleach
Read the instructions behind the bleach bottle and make a bleach solution in water. Then place the shirt in this solution.
Once soaked, keep checking for changes in colour. Mine took about 2 hours to reach the colour I desired.
Step 5: Wash It
Remove it from the solution and wash it till the water runs clear then let it dry.