In the world of guitars, terms plywood and laminate are used interchangeably. However, 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. 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 solid wood price range or unless specifically asked about the wood.
If a wood is not specifically labelled as solid, it’s safest to consider it to be a laminate. Laminate is also called as veneer, more so in the furniture industry.
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. These veneers are made by milling process called as rotary cutting. In this, a thin continuous layer is cut from log of wood similar to peeling skin from any round fruit.
This process is most efficient and retains ornamental grain pattern in comparison to other milling methods. This may make laminate guitars more attractive visually than solid wood instruments.
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 perpendicular direction, also referred to as cross-grained configuration. This arrangement results in high strength.
Ideally, central ply should be of 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 outermost veneer. This is usually not the case with cheaper guitars, where 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 are rigid and do not move but top can shrink and crack if the condition swings are great. Be extra careful with solid guitars if the conditions are dry or if fire is burnt in the house. It is recommended to use humidifiers in such times.
Plywood dont 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 laminate may separate over period of time due to excessive changes in temperature and humidity, leading to a loose section.
It is not easy to distinguish between solid wood and plywood. Some of the possible ways are:
Supplier and documents
Ask the manufacturer, dealer or seller.
Read through the sales literature and merchandise tags.
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. Only exception to the rule can be when specific origin of wood is mentioned, like Sitka Spruce. It is always better to ask again to be 100% sure.
Examine the guitar
Examine the guitar. Look for knot, pattern or texture on the outer wood. Then try to locate an identical corresponding pattern on the inside.
Look for plies on inside edge of 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. Cross section of laminate appears to be three layers sandwiched together and have little or no vertical grain.
Some manufacturers use plastic binding or inserts to hide the cross section. Presence of any binding material or any finish in the area is a dead giveaway that guitar has a laminated top.
With an inspection mirror, look underneath the top. Laminate tops have less finished coarse grained inside surface.
Plywood is not effective for tops as it can’t vibrate in a way required to produce good sound. So, only very inexpensive guitars or old models from some companies use plywood tops. Well designed plywood top guitar with fair price can be suitable for a beginner.
Solid top guitars improve with age. So, buying 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 guitar.
Laminate Backs and Sides
Back and sides of any guitar have different acoustic functions than that of the top. It maintains rigidity of sound chamber and helps in sound projection.
Guild began using laminates for back and sides in mid 1970s. Martin introduced low-end Sigma line of laminates to counter Japanese competition in 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.
Inexpensive guitars may even have fingerboards made of plywood. Good look at the end of the fingerboard above the sound hole can expose layers of lamination. Cap of wood is usually glued over the fingerboard end to hide the layers.
Laminate fingerboard is weak and potentially unstable. It is acceptable only on most inexpensive guitars.
Laminate Necks and Head stocks
Necks and head stocks are sometimes made by gluing several pieces of wood together. In such cases, these are also called as 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 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 laminated nature of wood, vibrations don't travel organically as in single piece of wood. Laminated guitars carry many of the tonal properties of the outer layer wood as this part vibrates with the string. But more accurate reflection of the tonal qualities of the wood used, depends on the type and quality of wood used for core and inner ply.
Its tone does not change significantly over time. The tone profile is flat with not well rounded bass or crisp highs.
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.