Hi Kara,
Thank you for all that information re thicknesses and weights. Yes I prefer to work in inches too. Using your pattern I made a pair of slobber straps yesterday, the long ones, and am very pleased with the result although they are not perfect yet. I used a sharp craft knife to cut the first one out but it seemed to take ages, so the next one I cut out with a pair of sharp scissors and the edges seemed much better! I found the hole a challenge to cut, but have ordered a steel punch of the correct size so hopefully that will make things easier too. The 3mm thickness, which is sometimes slightly thicker, does seem ok. Once I have some more spare time (juggling work, horses, dogs, housework etc!) I will attempt another pair.
Thank you again for all your help,
Littlelou