Mix 1 cup of isopropyl alcohol and ten drops of Daler Rowney FW acrylic ink.Pour into a spray bottle.
Start spraying the wig from roots to tips. Once covered grap a new section and then repeat spraying from roots to tips.
Do this until the wig is completely saturated and make up more mixture as needed. I found that it needed two cups to do the entire wig because mine was extremely long a medium length wig should only need 1 cup.
Leave to dry for about three days and then rinse in a bucket to get out any excess dye. If it is the desired color you want this is the time to shampoo and condition with synthetic wig shampoo and conditioner. Do this until the water runs clear so that it does not rub off onto your clothes or skin. Leave to dry again and then comb with a wide tooth comb to get out any knots that may have occured. Because it is such a long wig it tangles easily.