Material properties vary in relation to light depending on the atomic make-up of the material. For example; rocks reflect light, windows are see through, and wine is semi see through. The reasons for this can be described in three basic principles.
- Opaque- totally solid, does not allow light to pass through it. Will only reflect light, and causes hard shadows.
- Translucent- form can vary from solid to liquid, and is semi see through due to micro construction. Allows light to pass through but not fully so usually produces an illumination effect due to the pigment light passes through.
- Transparent- Totally see through, like glass, or water. It doesn’t restrict the light passing through, other than possibly reflecting and refracting it causing optical magnifying effects.
All materials fall between one of theses three definition principles with varying degrees. The object doesn’t have to be fully one of the principles, however the ranges tend to be defined effectively but are open to interpretation. This means one persons definition of transparent may not quite match another’s but for general description it’s a useful tool.