How to prevent creases and peanuts on defroster lines of back glass.

Method 1: Start with good prep, and make sure you prep the defroster lines thoroughly with either steel wool or a clay bar.

Method 2: If you’re wet shrinking, be more conservative with your slip solution. Peanuts are usually just tension points caused by an uneven shrinking, so make sure to take your time and don’t over shrink. If you’re dry shrinking, which is usually best, make sure you’re shrinking on low heat. When squeegeeing, don’t stretch the film when setting your middle line across, and squeegee everything straight up and down, always across the defroster lines, never along them. 

Method 3: Make sure you’re using quality film as cheaper material often has issues sticking to defroster lines.