Rapid Prototyping involved creating a working model of various parts of the system at a very early stage, after a relatively short investigation. The method used in building it is usually quite informal, the most important factor being the speed with which the model is provided.
There are water-and solvent-based -- also called oil-based -- polyurethane varnishes. Water-based polyurethanes are more environmentally friendly and safer to use than solvent-based, but they are not as resistant to wear and tear as solvent-based products.
A solvent is a liquid or gas that dissolves a solid, liquid, or gaseous solute, resulting in a solution. solute :- A substance dissolved in another substance, usually the component of a solution present in the lesser amount. Source(s): im a sutdent plus wikipedia and a dictionary ;) troubler Â· 8 years ago.