Seconding the use of inkscape.Loads of tutorials & facebook groups.I also have a laser cutter/engraver so combine it with k40 whisperer.
It cuts out patterns nicely & engraves veg tan leather well.I also combine leather & wood on some items but could easily cut the keyrings from leather.
Keyrings.
To update this thread,new polymer notes are now in circulation.
The polymer £5 note is125mm x 65mm
The polymer £10 note is 132mm x 69mm
The polymer £20 note will be 139mm x 73mm Due to be issued in 2020 (the current paper note is 149mm x 80mm).