Permithin, it's a spray.  You apply it to clothes, packs and boots only, not your skin.  Works pretty good.
Permethrin has been used in animal flea/tick/fly/mosquito sprays forever.  If you use the concentrate be very careful it can cause illness in humans in high doses.  It it derived originally from plants and has a pretty long history so it's side effects are well known. 
That said I usually use Frontline or advantage just during the tick season.  I spray my clothes with cutter/off or a similar because I work in the brush and may or may not have a long term tick caused problem.  
I have tried the fabric sheet for skeeter repellent it works ok.