The first time I flat ironed in September of 2010, I was really nervous and only set it to 350 and eventually 370 when I realized I wasn't getting that slick look.
This last time, I had to crank it up to at least 410-420 to get the results that I wanted.
Now granted, the roots were pressed at the salon and also flat ironed with the marcel flat iron on a Friday and by Saturday the shaft was all frizzy and I had to flat iron again. I just knew I was getting damage but nothing really noticeable so I'm happy!!!!