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High-pressure laminate (HPL) is a durable material used in flooring, cabinetry, and other furniture applications. Around the late 1990's guitar companies began to utilize HPL in the construction of the bodies of their acoustic guitars. The material's popularity is increasing due to pioneering companies such as Martin & Co.

Composition
High-pressure laminates are formed from multiple layers fused with phenolic resin under high pressure. The first being a clear protective layer covering the decorative layer underneath. The decorative layer allows for custom designs of any kind to be displayed. Typically guitar manufacturers choose wood-grain or all black. The bottom layers comprise the bulk of the material and are made from kraft paper (the brown paper used in paper bags) soaked in phenolic or melamine resins. The sheets are dried and placed in their respective layers under a hydraulic press where they are exposed to over 1000psi (~7MPa) to induce bonding.

Famous Guitars
HPL guitars are not pervasive in the music scene. Some artists, such as Ed Sheeran, use them as their instrument of choice. Sheeran has been seen performing with a Martin LX1 and LX1E on many occasions throughout his career.

Martin Guitars
Martin's series X contains both their wood topped, HPL back and side guitars along with their all HPL bodied guitars. The production of these models started in 1999 and there are currently 7 models for sale by the company. Each model contains X pattern soundboard bracing and are acoustic-electric.

Benefits
The validity of the material is debated within the guitar community, but some benefits are evident. The manufacturing process is consistent as the material is uniform unlike wood. Each HPL guitar will sound about the same as the last. The material is extremely wear resistant. Scratches, pick-wear, liquids, heat, and changes in humidity have little effect on the material, unlike traditional acoustic guitars which should be held at a specific temperature and humidity to avoid warping. In terms of production, HPL is also much cheaper than lumber and is much more sustainable. Rare trees are not needed for the material's production as any form of wood pulp can be used to create kraft paper substrate. Thus, companies see more profit as their scrap wood can be recycled into HPL.

Drawbacks
For some, the consistency of manufacturing is a drawback of the material. The guitars no longer have an entirely unique sound profile as the same sheet of HPL could be used in many guitars. HPL is hard to the point where it rarely breaks, but when it does, the brittle material shatters. Unlike wood guitars which typically break along the grain, HPL guitars end up in many non-uniform pieces. Repairing HPL guitars is difficult and it will certainly not look the same as when it exited the factory.