Returning t`mill after a break, partly spurred by Sketchup getting .stl export that works.

Wanting to mill smallish, 3040 , mould masters for dolls house and model railway building features.

Take molds from master machined plug is the idea, but what to use for the plug is the question that would appreciate the input of the panel.

1. Modelling Board , as in high density PU foam, am already a fan of using celotex/kingspan for trial cuts , lot more forgiving on wrong Z than MDF :-) and cheap. HD PU is hard to obtain in small quantities or prices below what presume McLaren F1 pay, also wondering about surface finish unless go to very high density/cost board. Any hints on suppliers?

2. Machinable Wax, as in blue Trycut or mix your own with paraffin wax and poly bags, looks like an economcal possibility, but wonder about home mix inhibiting cure with latex or silicones. Any experience to share?

3. Plaster, read varying reports but seems if its machined a bit green or damp , dust shouldn`t be a problem, seems ideal for latex as it will release easily , wins on cost. Again any words of wisdom from anyone?

4. Balsa, Jelutong , bass wood seem to be traditional patterm making materials but guessing grain and splintering can be issues and will need coated with a release.

Appreciate any input