How do I hold my knife to prevent blisters when chopping? I have a Wusthof Trident Classic 8" Cook's knife that I use for chopping.  I thought I was holding it properly but when chopping for extended amounts of time I end up with a blister on the edge of my palm at the base of my index finger where it rubs on the top edge of the knife.

I hold the knife where the blade and handle join together, between my thumb and index finger.  I have no problem with arm fatigue or tension, just the rubbing.

Can someone recommend some tips or point to instructional resources that can help me prevent this? Do I just put a barrier on the spot where it rubs?
Friction blisters are usually the result of continuous rubbing on skin that hasn't toughened up.

If you are getting blisters with normal amounts of chopping, either your knife is moving in your hand more than it should, or you are exerting more force than you should need.

Focus on your technique. Are you pushing down with the whole palm, the front of the palm, or the back of the palm? Are you guiding or forcing with your thumb and forefinger? Is your knife sharp and heavy enough for the materials you are cutting through? Are you using a circular motion to chop?