For anyone concerned with slip-joint usage, don't be. The other day at work I had to cut off a section of a rug that is used to cover up computer cables. The thing was in bad shape and was curling at all the corners. It was a tripping hazard for sure! Without any thought about slippage or usage anxiety I took out my Texas Jack and went right to work. It went through the rubber and nylon? with no closing or hanging up. This was some tough stuff to cut and the Jack needed a little stropping afterward, but the job got done with no issues. Don't worry about using your slip joints! Use your GECs, CASEs, Remingtons, Schrades, etc. Buy them, coon finger them, and use them! That is what they are for.