Types of plywood

There are two main ways to classify plywood: by core construction and by veneer grade.

By Core Construction

Veneer core plywood

This is the most common type of plywood. It is made with thin sheets of wood (veneers) that are glued together in a cross-grain pattern. The number of veneers can vary, but there are usually an odd number of veneers to help prevent warping.

MDF core plywood

This type is made with a core of MDF (medium-density fiberboard) that is sandwiched between two veneers. MDF is a stable and strong material, making it a good choice for applications where strength and stability are important.

Lumber core plywood

This type of plywood is made with a core of solid wood lumber that is sandwiched between two veneers. It is very strong and stable, making it a good choice for applications where high strength is required, such as countertops and cabinets.

By Veneer Grade

The veneer grade of plywood refers to the quality of the wood veneer on the face and back of the plywood. Veneer grades are typically denoted by a two-letter code, such as A-A, A-B, or B-B. The first letter refers to the grade of the face veneer, and the second letter refers to the grade of the back veneer.

• A grade veneer is the highest quality veneer. It is free of knots, holes, and other defects.

• B grade veneer may have some knots, holes, and other defects. However, these defects will be small and tight, and they will not affect the strength or stability of the plywood.

• C grade veneer may have large knots, holes, and other defects. It is not recommended for applications where appearance is important.

Here are some of the most common types of plywood, classified by both core construction and veneer grade:

• Softwood plywood: is made with veneers from softwood trees, such as pine, spruce, and fir. It is the most common and least expensive type of plywood. It is a good choice for applications where strength is not critical, such as sheathing and subflooring.

• Hardwood plywood: is made with veneers from hardwood trees, such as oak, maple, and birch. It is more expensive than softwood plywood, but it is also stronger and more durable. It is a good choice for applications where appearance is important, such as furniture and cabinets.

• Marine plywood: is made with waterproof glue and veneers that have been treated to resist moisture. It is a good choice for applications where the plywood will be exposed to moisture, such as boats and outdoor furniture.

• Aircraft plywood:  is made with high-strength veneers and glue. It is used in the construction of airplanes and other aircraft.

• Flexible plywood: can be bent without breaking. It is made with thin veneers that are glued together with a special type of glue. It is used in a variety of applications, such as making curved furniture and boat hulls.

When choosing plywood for a project, it is important to consider the application and choose the type of plywood that is best suited for the job.