The mouldings pictured are the basic profiles of the framing industry. Profiles maybe wider, taller, have a deeper rabbet. They may be decorated with various finishes and embellishments. The quality of wood used in the finishing methods may vary with each manufacturer.
There are trends in the framing industry just as in decorating and clothing. The companies that design mouldings take into consideration the colours, furniture, and types of art that are popular and make mouldings to suit. Mouldings may be discontinued when they go out of style, although many "classics" remained available for many years.