if you want a cheap base to leave on its own or add onto a wooden block or frame just head down to your nearest art shop and buy some fine casting plaster .
it can be used for almost everything !
to make road (cobbled or stoned):
mark out your overall shape for your road
pour diluted plaster (thin cosistancy) over tour area using somthing to mask the areas you dont want plastered off.
when semi dry (and be quick) etch in a stone pattern or a cobble pattern depending on what you want to achieve .
when dry paint with an panzer greay colour
oil wash with shades of brown
mix up a pigment (mmp or mig or artists) in a very thin mix
and wash the road with several coats
dry brush with lighter greay
add static grass sparingly depending on condition of the road
and for scenery :
firstly get a solid box wich wont warp with the water in the plaster(make sure it has edges so you can form hills/bumps /whatever!!
) pour in the plaster and add some sand or fine grit/ railway gravel (oo /1/76 scale !!) and when semi dry stipple with old brush and press in tracks or wheel marks
paint similar ro road technique but using colours suitable for what area your modle is based in !!using run of the mill p.v.a randomly stiple static grass on and then fimally gine it a dry brush of misting with airbrush
spammers
