If the medal is very thick, do not pour a cast that is as thick; the cast just needs to be half as thick as the medal. But if it is thin, make a cast that is of the same thickness. Do not forget to make vents in the cast or the whole matter will fill with bubbles.
at left bottom margin of folio 158v
Never forget to oil the cast with wax when you cast herbs or flowers, otherwise it will break and cannot be taken out.