On Thu, 28 Aug 2008 13:57:25 +0100, wrote:

My most recent one is an Irwin which folds open ...

And locks open? Folding knifes that don't lock are a menace in DIY.

If it does lock don't carry that on the street! Locking blade knives were
outlawed long before the current knife laws.

Using it a couple of days ago to cut plasterboard

The fingers of my left hand will tell you that this is not a good idea.
Very nearly took the top 1/2" off the second and third fingers around
about 20 stiches needed to sew them back on.

Cut plaster board with a "Stanley" saw blade *much* safer and probably
quicker. Unless you are doing the scrore and snap.

http://www.screwfix.com/prods/57220
http://www.screwfix.com/prods/36570

The second might be a bit vicious, the first fits a normal Stanley handle:

http://www.screwfix.com/prods/72804

This is the "Stanley" knife I use, able to take a selection of blades, is
retractable and very sturdy not like the plastic stuff.

--
Cheers
Dave.