i tried a few of the different techniques mentioned, and had the best luck with the one i will share here. a few notes before getting start though - it obviously helped that finn has really light hair, as it just soaked up the pigment, but i think this would work with darker hair too - it dries kind of chalky and coats the hair, rather than soaking in and dying it, so it's worth a shot. also, make sure you use CHALK pastels (not oil pastels, not sidewalk chalk...) - it has the perfect vibrancy and texture to work with, and washes out relatively easily. You can find it at most art supply stores (thought the michaels near our house did NOT have it) or on amazon HERE.
you will need:
pastel chalk
water
a comb
a flatiron
hairspray
hairclips or bobby pins
an old towel or drop clothe for the floor around you (fair warning, it gets kind of messy!)
start by sectioning off the hair into the chunks you want to colour. begining with the fist section, wet the hair with bit a bit of water on your fingers until it feels damp. then wet the chalk by running it under the tap for a few seconds and start rubbing it onto the hair. i found it easiest to work in smaller segments, keeping the hair segregated with clips as we moved along. once the section is colored to your liking, take your flat iron and run it over the hair until its dry. i found this step was really important and it dispersed the colour more evenly, and helped the chalk to 'set' so it didn't dust off as easily.
once done, style the hair as you want, and spray a light misting of hairspray for the final 'set'. to wash out, use lots of shampoo and wash as needed. it might take two or three washes to get the colour completely out, but most will wash out right away.
in some of tutorials i read, they mentioned using a hairdryer instead of a flatiron. i can see that working in a pinch, but imagine it would be a lot more time consuming, and a lot messier. fair warning that this was a relatively dusty project- there was chalk dust and crumbs all over finns clothes, my hands and the bathroom floor, but the results were well worth it, i think. finn was REALLY stoked with how it all turned out!
