In the world of guitars, the terms plywood and laminate are used interchangeably. However, the Guitar industry prefers to use the word laminate exclusively. Laminate is made up of several layers of wood glued together. 

Professional grade acoustic guitars have their top, back and sides made up of solid woods, while beginner and intermediate-grade guitars are made partly or even entirely with plywood and are sometimes also referred to as plywood guitars. Almost all acoustic guitars with a price tag under $1000 are made of laminate sides and backs. Most inexpensive guitars even have laminate tops.

Real solid wood guitars sound much better and get better with age, a process known as opening up. The limited supply of these exotic woods and the elaborate processes makes it difficult for these varieties to be available at modest prices.

Most manufacturers and dealers do not indicate that they use laminates unless they want to sell you guitars in the solid wood price range or unless specifically asked about the wood.

If wood is not specifically labeled as solid, it’s safest to consider it to be a laminate. Laminate is also called veneer, more so in the furniture industry.

Laminate Construction

The majority of guitar laminates are three-ply construction. 

The Outermost plywood is the visible one and is a finished veneer made of mahogany, maple, rosewood, etc.

The Central Ply, or the second layer, is also known as the core. It is glued with the outer layer with its grain pointing in the perpendicular direction, also referred to as a cross-grained configuration. This arrangement results in high strength.

Ideally, the central ply should be of the same wood as other layers. However, inexpensive and cheap guitars may have even junk wood or a composite. 

The Inner Ply, visible through the sound hole, should usually be the same wood as the outermost veneer. This is usually not the case with cheaper guitars, where the need for visual appeal is minimal. 

Some manufacturers use inner ply with grain patterns which makes it harder to visually tell if it is solid or plywood.

Stability And Durability

Laminates are more stable and durable than solid woods. Guitars are typically built-in 40 to 50% relative humidity conditions and remain best under these conditions. Solid guitar tops are glued in the longitudinal middle and to the bracing to provide stability along with their natural resins. 

Bracing is rigid and does not move but the top can shrink and crack if the condition swings are great. Be extra careful with solid guitars if the conditions are dry or if a fire is burnt in the house. It is recommended to use humidifiers at such times.

Plywood doesn’t crack in dry conditions like solid woods but can swell or distort in humid ones like poorly seasoned solid woods. 

Generally, laminates hold very well through short-term climate changes, abusive treatment, and travel. Long-term tests and their results are not well documented.

Plywood shatters when punctured making it difficult to repair. What is a small patch repair job on solid guitars, requires cutting out and replacing an entire section in laminate. 

Plies in the laminate may separate over a period of time due to excessive changes in temperature and humidity, leading to a loose section. 

Detecting Plywood

It is not easy to distinguish between solid wood and plywood. Some of the possible ways are:

Supplier And Documents

1. Ask the manufacturer, dealer, or seller.
2. Read through the sales literature and merchandise tags.
3. Most solid-top guitars are described as solid spruce or solid [top wood name]. If the description is “spruce top”, without the word solid, it is in all probabilities, a laminate top. The only exception to the rule can be when a specific origin of wood is mentioned, like Sitka Spruce. It is always better to ask again to be 100% sure. 

Examine The Guitar

1. Examine the guitar. Look for knots, patterns, or textures on the outer wood. Then try to locate an identical corresponding pattern on the inside.
2. Look for plies on the inside edge of the sound hole. This is most difficult to hide in the area under the fingerboard. In solid top guitars, wood grain is visible through the entire width of the top like a ladder. The cross-section of laminate appears to be three layers sandwiched together and has little or no vertical grain. 
3. Some manufacturers use plastic binding or inserts to hide the cross-section. The presence of any binding material or any finish in the area is a dead giveaway that the guitar has a laminated top.
4. With an inspection mirror, look underneath the top. Laminate tops have less finished coarse-grained inside surface. 

Laminate Tops

Plywood is not effective for tops as it can’t vibrate in the way required to produce good sound. So, only very inexpensive guitars or old models from some companies use plywood tops. A well-designed plywood top guitar at a fair price can be suitable for a beginner. 

Solid top guitars improve with age. So, buying a solid top guitar with laminate back and sides is perfectly reasonable. These may not be sounding really good but may sound better than inexpensive all solid wood guitars.

Laminate Backs And Sides

The back and sides of any guitar have different acoustic functions than that of the top. It maintains the rigidity of the sound chamber and helps in sound projection. 

Guild began using laminates for the back and sides in the mid-1970s. Martin introduced a low-end Sigma line of laminates to counter Japanese competition in the 1970s. In recent times, laminates are even being used in good flattop guitars and some electric archtop guitars. 

Even professionals use laminate guitars when they

• play in a band where the sound is not exposed.
• plug in their guitars and control sound quality through electronics. 

Laminate Fingerboards

Inexpensive guitars may even have fingerboards made of plywood. A good look at the end of the fingerboard above the sound hole can expose layers of lamination. A cap of wood is usually glued over the fingerboard end to hide the layers.

The laminate fingerboard is weak and potentially unstable. It is acceptable only on most inexpensive guitars.

Laminate Necks And Head Stocks  

Necks and headstocks are sometimes made by gluing several pieces of wood together. In such cases, these are also called laminates. Lamination in these parts by juxtaposing cross-grained sections imparts strength. 

Materials And Tones

Laminate guitars can bring out certain color variations and grain patterns that can be very pleasing to the eye. They can be made to look very comparable to solid wood options at much less cost.

Each kind of body wood has its own characteristic full and resonant sound. Maple has a bright sound, rosewood punchy, and mahogany sweet. With age, opening up happens, whereby the wood fibers gradually loosen to provide clear & warm sound and additional volume. 

Many experts say that due to the laminated nature of wood, vibrations don’t travel organically as in a single piece of wood. Laminated guitars carry many of the tonal properties of the outer layer of wood as this part vibrates with the string. But the more accurate reflection of the tonal qualities of the wood used depends on the type and quality of wood used for the core and inner ply. 

Its tone does not change significantly over time. The tone profile is flat with no well-rounded bass or crisp highs. 

Conclusion

While the difference in sound quality is very distinct between all-laminate, back and sides laminate, and all solid wood guitars. But beyond a certain price point, there is a diminishing return on sound quality.