if doing one inch board breaking, u prefer using palm or fist?

Er, palm. That is, the heel of the palm. I really wouldn't want to be doing any breaking with the fist until I toughened it.

If given the option, I would use my palm. But I've done both as they were required.

The palm break is easier on the hand. I have done both, and prefer palm heel on the board.

I prefer the fist as I am able to focus on my technique much more then on a palm strike. After all we do how many punches in class each week. If talking garden block, I vote for palm all the way.

I have done both as well, but I prefer fist. Maybe it's because I have a screw in my right wrist from an old lacrosse injury and it's tough for me to move my wrist back far enough to execute the palm strike well. (I can do it, it's just uncomfortable.)

The left hand I don't mind either fist or palm. I think people get a little intimidated about using the fist as they think it will be painful, but if you execute the technique properly, you'll go through the board and there will be nothing to worry about.