hardening seedlings to go outside?

How big should my seedlings be before they go outside? And what are the proper steps to 'harden' your seedlings before putting them outside? + rep for anyone with good info.

check out my babies.

thier about 2weeks from seed before i put them outside.

and use a fan to stengthin your stems. wont look much but will help with rain storms.

you need to prep them for three things, sun, wind, heat. the first two are not too hard. first, put them out in the morning before sunrise and let the elements have their way with them just be sure to bring them in as soon as the seem stressed. the third is a bit tricky you need to let them dry out to the safe limit a little bit more each day untill they can take a hot dry day in stride. once again be sure to bring them in if they get over stressed. or... you can do what we do, just put em out and let the strong survive(natural selection). thanks Darwin! we only do that because we are dealing with hundreds of starts and can be worried about making a few weaklings survive. in our evironmet even a robust adult may not make it in the peak of summer drought.

I have a question, I have a about 60 plants that are about 1 1/2 months old under a 400w H.I.D., does the H.I.D. harden them off as far sun burn goes, was wondering because there's no way that i can harden mine of before going out under the sun.