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is your hair long or short now? If you cut it short for Gaara are you will to wear a wig in order to do the tenten costume? Lots of guy characters have short hair, however not always the same color or style. Girls hair is typically done easier with wigs it seems

I think really short Gaara like wigs do exist >>

Personally, I've only cut my hair when I was cosplaying as Paine, but I wanted to cut my hair short to start with. I mean, do you want to have the Gaara hair until it grows out or do you like your hair as it is right now?

Get a hair dye kit form your local drug store or whatever, Lots of places have them, and lots with the shade of red that'd work good, and with short hair it's pretty fool prooof to get it all through your hair.
It's like 1/8 of the cost to do it yourself and way easier.
And as for the other cosplay hairs, just get yourself a wig and style it.

I've cut and dyed my hair for charaters more than once. Honestly before trying to cut your hair and then convince your mom to let you dye it, see if you can't find a wig.

The only way I cut and dye my hair is if I have more than one thing that works for it or I can chage it mid con, like last Jacon I cut my hair like Poemy Watanabe from Puni Puni Poemi (excel spin off) and dyed it like a month before a color that was slightly too dark to allow for fading (I'd also done this color before so I knew it would fade the color I needed ^.~) I then bought hair bleech and took it to the convention with me, now one of my freinds is actually the person who cuts my hair so she trimmed it at the con and I bleeched it there so I could do Poemy on friday and Tohma from Graviation Saturaday. That worked out nicely since my hair actually had a month to rest between dyings. Rapid dye jobs are baaaaad.

I would just wear a nice wig. That always makes life easier, and there are plenty of sites with decently priced wigs in every color imaginable. ^_^ All you have to do is style it and put it on, and you won't have to worry about dealing with the hair cut/dye later if you happen to change your mind.

I would say do a wig for the Gaara hair, if you get a wig that you have to cut yourself to make it short enough, make sure that you see that the scalp of the wig wont show too much with it that short and thus makeing it look pretty tacky: I have done that before and should have figured it would happen cause it was a cheap wig.