I've use about everything at one time or another, including Xacto, Osbourne, Olfa, Hyde, Tandy, etc. but recently I ordered a couple off Ebay from a place called "Haleandco."
These were Barnsley brand knives out of Sheffield. I got the 3-inch heel paring knife and the "Paris curve clicker's knife" to start with, and I'm going back for a few more.
The clicker's knife has an inside curve like the Xacto wood carving blade, but it is a bit different edge-wise. It is great for cutting thin chrome strap material or going around a pattern in 4-5 oz vegtan. I've had other knives including Xacto pull on chrome. This Barnsley curved blade cuts clean.
I have used the 3-incher for cutoff and inside square cuts, and it's the best yet by far.
At a glance the heel paring knife looks like a Tandy special or one from Hyde or Osbourne, but it's thinner and you can put a much more extreme edge on it.
These knives are carbon steel, and they aren't hard to sharpen at all. They require fine stone touch-up and stropping frequently but they cut at a touch. - mac
