Yep...fiberglass batt. At least R-19 in the walls and R-30 in the ceiling. With the garage insulated well, you keep it shut up with minimal light coming in, you go out into the garage on an 85 degree day, it will feel like it is air conditioned. My garage is well insulated and on a hot, humid day, is probably 10-15 degrees cooler until I open a door or two up. Besides that, the insulation will pay for itself in a year or two depending on how much time you spend in the garage. And with the high prices of heating nowadays.....