A cheap way to get a better grip on the bar

Ever noticed that when you into your pull up work out, the grip starts to get tired, your hands start to sweat, and suddenly its not pull ups that your failing on, but just holding onto the bar?
don’t get me wrong I believe that developing grip strength is very important when doing exercises like pull ups, i could list the benefits for days (I may do at some point soon :L) but if you want to test your gripping strength, something like a thick bar is better than wetting up your hands before every set.
I am currently training one arm pull ups (cheeky picture of me below), so every issue that you get with regular pull ups is doubled when you switched to one arms. And I do not want to be having to deal with slipping off the bar half way through my set. You can always use chalk But an impromptu chinning session when you are out and have some spare time will leave you chalk-less and slippery, unless you want to carry your chalk around with you.

I was training a client one day, we were doing super sets with chin ups and farmers walks with fat gripz. Into the 3rd or 4th set, his hands started to slip on the pull ups, so we wrapped one of those Pilates bands around the bar and it worked perfectly.

These bands can be brought off Ebay for under £5, simply cut a couple of 3-5 inch sections off and wrap them around the bar when doing pull ups and enjoy the friction.
Enjoy the gains,
Alex