I have categorized each of the before and after pictures based on their manufacturer and construction. This is just a basic outline of the construction and materials used in each of these boards. 

EPOXY SANDWICH BOARDS: These boards are constructed with styrene based cores, plus rigid sheet foam and/or wood veneer, sandwiched between high strength reinforcements (fiberglass, carbon, kevlar, dyneema etc.) and laminated with epoxy making it an "epoxy sandwich construction" that produces a very strong board. For everything you ever wanted to know about epoxy boards go to Eva's aka "The Board Lady" website - www.boardlady.com 

PAINTED SANDWICH BOARDS

SURFTECH - TUFLITE: Constructed with EPS Foam, Fiberglass, Rigid Sheet Foam, Fiberglass laminated with Epoxy; and Paint.

BOARDWORKS: Constructed with EPS Foam, Fiberglass, Rigid Sheet Foam, Fiberglass, laminated with Epoxy; and Paint.

CLEAR FINISHED SANDWICH BOARDS:

SURFTECH - TL2: Constructed with EPS Foam, Fiberglass, Acrylite (a high density foam) and Fiberglass laminated with Epoxy.

FIREWIRE: Constructed with EPS Foam, Corecell (a high density foam) Balsa for the rails, Fiberglass laminated with Epoxy.

SURFTECH - WOOD VENEER:  Constructed with EPS Foam, Fiberglass, Wood Veneer, Fiberglass laminated with Epoxy.

EPOXY SINGLE SKIN: These boards are considered single skin because they have just fiberglass covering the foam blank.

XTR: Constructed with Extruded Polystyrene Foam (closed cell foam stiffer than EPS) Fiberglass laminated with Epoxy.

EPS: Expanded Polystyrene Foam, Fiberglass laminated with Epoxy and Paint.