Thanks for the compliments Guys.
Nothing special is done to the cutting path - the important thing is the tip offset of the cutting knife (the smaller the better) and it's freedom of rotation. The 90 degree corner radius, which is produced by drag knifes, is only just perceptible and in many ways it is an advantage in so far as that the vinyl may otherwise easily tear at a sharp corner when weeding. For really small signage the very thin vinyl (used for RC model decals etc.) is superb.
Now that Winter is almost here I will try to increase the X file page on my website to cover more aspects (RSA encryption and factoring of large numbers).
Tweakie.
btw. I think Gertrude is a mill (with rotary axis).