Stout heart plywood

Compromise between plywood and blockboard has a thicker centre veneer (stout heart) with usually 2 normal outer veneers on the outer faces of this inner core

Plywood

Standard plywood has an odd number of veneers that are laid at 90 degrees to each other. This crossing of the layers gives the board its high strength and low shrinkage characteristics. The quality of the plywood depends on then number of veneers, the quality of the timber in the face veneers, the finish applied to the face veneers (like sanding) and the quality and type of adhesive used to glue the veneers together. Birch Plywood Grades (here)

Blockboard

Traditionally blockboard had birch faced veneers with softwood core. the core strips were 25mm wide. this made a very usable board. Although if the core strips distorted with shrinkage then these pulled the face venerers and made a slight rippling effect on the face that showed if the board was veneered and polished.

Eastern blockboard

A modern - less expensive - replacement for traditional blockboard made from far eastern timbers with laminated cores up to 75mm wide

Lamin Board

Similar to traditional blockboard but the core strips are smaller maximum 7mm wide (laminated strips). These strips shrink less and do not distort the face of the panel will ripples so are lamin board makes a better substrate for veneering work.