Wood Pattern Materials:
Most common

Suger Pine: Pine is probably the most used pattern material. It's stable, closed grain and is shaped easly. Pine holds up well for short run patterns, 50 or fewer molds. This wood is pitchy and will gum up a sander. It take a finish well, either laquer or shellac but will require at least 3 coats.You can get more molds if the pattern is maintained and stored in a properly. If stored in a damp area the wood will swell and split glue joints regardless of finish.

Mahogony: Honduras mahogony is used for higher use patterns, 50 or more molds. This is an open grain wood, but the grain is tight enoughthat with 3 to 4 coats of some finish it will seal well. It's red in color and hard. Also leaves a purple stain on your fingers, A properly mantained pattern can last through a few hundred molds. There is another mahogany, Philipine mahogany, is open grain wood that is not stable and can contain a lot of slash grain. It will work for the pattern, but will not store well and has a tendency to change shape over time.

Maple: Maple works for close tolerance patterns. It's stable, and is probably best suited for machined patterns. Closed grain wood that will only require 2 coats of finish. It will last a little longer than Honduras mahogany in normal foundry use.

Jelutong: This wood has many of the same characteristics as pine. It's a uniform, open grain wood that is little less stable but easer to carve than pine. The weight is about the same as pine.

Poplar: Poplar is a hard wood, but not as hard as maple, nor will it last as long in the foundry as mahogany. Compared to other hard woods it's less expensive. A good cross between maple and pine. It's a little fuzzy when sanded on a disk sander, which will come off after the first finish coat has been sanded. Stability is ok, it can move quite a bit when cutting.

Alder: This is one I like. Similar to maple, but not as hard. It lasts about as long as mahogany in the foundry. Closed grain and stable, finishes in 2 to 3 coats. All these woods can be machined, but this one seems to have the best overall characteristics for a light CNC machine.

MDF board: I have to admit I haven't used this one much, haven't wanted to. It's dusty; it stinks and makes me itch. It does machine well because it's completely grainless and can be carved. The few times I have used it, I've noticed it's not very stable in a damp climate, it has a tendency to swell. Once the pattern was finish sanded it took several coats of lacquer to seal it.