Materials have a cost and optional properties, as well as weights for those properties.
And stability, which affects the size of the white bar representing the properties.

Properties are variable between 0 and 1 as a bar graph. Weights are between the same values
and is how much the property resists being changed when the material is combined.

A goal material is listed as a bar graph of properties. Grey doesn't matter, red is an area
that must be avoided, and green is an area that must be reached. If the white bar of a
property is partially in red, or partially out of green, it is unacceptable. Either use
more materials or more stabiliser.
