Keyboard’s Plate
Custom mechanical keyboards allow you to choose between different materials for the plate (called plate), which is the layer that keeps the switches stable on top of the PCB. The material of the plate greatly affects the typing feeling and sound of the keyboard, as well as weight and aesthetics. Below we will see the most common materials explaining in a simple way their advantages, sound profile, typing sensation, flexibility / rigidity, weight and aesthetics, with some advice on which ones to choose based on use (gaming, writing, modding, etc.) and combinations with switches and mounts.
Aluminium
• Advantages: It is the most common plate material in custom keyboards, appreciated for its overall balance. Aluminum is lightweight yet strong, easy to cut (CNC), and relatively inexpensive. It offers excellent construction precision and durability.
• Sound Profile: Produces a crisp and bright sound, with quite high and metallic tones. Compared to plastics, the sound is more clicky, although slightly less ringing than even denser materials such as copper/brass. In practice, the aluminum plate emphasizes the high sounds of the keys and can present a slight metallic ping (resonance) if no damping devices are used.
• Feel: Offers responsive and firm typing. As a relatively rigid metal, it returns solid feedback with every press, while maintaining a slightly softer touch than brass or steel plates. Many consider it an ideal middle ground between flexibility and solidity: the keyboard with aluminum plate is stable without being excessively hard.
• Stiffness/Flexibility: Quite stiff. The aluminum flexes little under normal pressure, ensuring stability to the switches. However, it is not extreme: it is less rigid than brass or steel, and slightly more flexible than the latter. In practice, it allows a slight elasticity (especially when combined with soft mounts) but overall tends towards rigidity.
• Weight: Lightweight. One of the advantages of aluminium is its low weight. This helps to keep the keyboard more manageable. For the same size, it weighs less than brass and steel, but more than plastic materials such as PC or POM.
• Aesthetics: Thick aluminum plates are anodized in various colors, offering a clean and premium look. Although the plate is usually internal, it can be glimpsed between the frets: anodized or brushed aluminum has an elegant look. It does not develop any layer (does not change its appearance over time) as brass does.
• Recommended combos: It is an all-rounder plate; it is good a bit for all uses. With tactile switches it offers a good balance between solidity and feedback (great for writing and mixed use). With linear switches it gives a fast response and clear sound, pleasing to those who want a more audible click. On a gasket-mount keyboard, aluminum is often ideal because it adds stability; on more rigid mounts (e.g. top mount) it will be very rigid overall, so it depends on taste. In general, if you're on the fence about the material of the plate, aluminum is a safe and balanced choice to start with.
Brass
1. Advantages: Brass is a dense material and highly valued in high-end assemblies. It is chosen to give the keyboard a premium touch in terms of weight and solidity. Brass is extremely sturdy and durable, and many find it ideal for a "solid" feel under the fingers. It can be polished to shine and is a hallmark of fine builds.
2. Sound Profile: Generates a deeper, more resonant sound than aluminum. It is often described as a warm, full clack - the brass accentuates the low-mid frequencies, giving a satisfying "thock" tone to the keys, while being able to introduce a slight metallic ping due to the rigidity. In other words, the sound is less high-pitched than aluminum and more full-bodied. Many appreciate it precisely for this very "mechanical" full-bodied sound.
3. Feel: It offers very rigid and stable typing. Each press on the key gives a sharp and decisive feedback, with practically no flex. The feeling is firm and responsive, ideal for those who like to clearly perceive each actuation. Some may find it a little harsh in long writing sessions, but others love the "planted" feel that brass provides.
4. Stiffness/Flexibility: Very stiff. It is stiffer than aluminum and any plastic; it flexes very little if at all in normal use. This lack of flexibility means more stability but also less shock absorption: the bottom-out (when you press the button fully) is firmer and less damped.
5. Weight: Heavy. The brass adds a lot of weight to the build, helping to give that feeling of a sturdy and stable object on your desk. A brass plate can weigh several times a polycarbonate plate. This extra weight is often sought after in quality builds to increase solidity (but makes the keyboard less portable).
6. Aesthetics: It has a very attractive golden color. A polished brass plate shines through the key spaces and is visually appealing. Over time, brass oxidizes slightly forming a dark patina that many find fascinating (vintage look); Those who prefer shine can polish it periodically. In any case, it gives a luxurious character to the keyboard.
7. Recommended combos: Recommended for those looking for maximum stability and an authoritative thock sound. It is very popular with tactile switches: for example, many find that Holy Panda-type tactile switches on brass plates have excellent sound and response. The solidity of brass emphasizes the "bump" of the tactile both in terms of feeling and sound. Even in gaming it can be satisfying if you want immediate feedback and keys that return promptly (thanks to the stiffness). However, on long writing sessions it may tire if you prefer a softer touch. Brass often performs best with gasket or suspended mounts (to mitigate its hardness a bit), while on a rigid frame mount it can be really uncompromising (very hard fingerboard). In short, ideal for those who love a rigid and heavy tank keyboard, especially with tactile switches.
FR4
• Advantages: FR4 is a composite material based on fiberglass and epoxy (the same as PCB printed circuit boards). Its strong point is its balance: it offers intermediate characteristics between metal and plastic both in terms of flexibility and sound. It's also cheap and easy to get, making it great for experimenting (many modders try alternative FR4 plates to test different sounds and feel without breaking the bank).
• Sound profile: Neutral and controlled. FR4 is often referred to as bland (neutral) in sound, because it does not overemphasize either the metallic treble of metals or the muffled bass of plastics. The result is a medium-tonal, balanced sound. Some describe it as a less ringing clack than aluminum but more "present" than polycarbonate. Being the same material as the PCB, the typing sound tends to have a uniform resonance with the board, without any annoying spikes.
• Feel: Provides balanced typing. The FR4 is neither too stiff nor too soft: it gives fairly consistent feedback, but with a slight elasticity that makes for a comfortable experience. Many find it pleasant because it combines stability and a hint of softness on the bottom of the stroke. In practice, typing on an FR4 plate you perceive a less hard bottom than on metal, but still firmer than on pure plastic.
• Stiffness/Flexibility: Intermediate. More flexible than aluminum but less than polycarbonate. It allows for a certain level of flex under pressure (especially on longer layouts, e.g. spacebars), helping to dampen the shocks a bit. At the same time, it retains enough stiffness to avoid the feeling of "rubbery". It really is halfway between the two worlds, which makes it a versatile choice.
• Weight: Medium-light. Being fiberglass, it weighs less than metals (much lighter than brass and steel, and a little lighter than aluminum). This keeps the total weight of the keyboard low. However, it is denser than pure plastic, so not the lightest of all.
• Aesthetics: Usually, FR4 plates are black (like PCBs) or sometimes dark green, often with a visible fiber pattern at the edges. They are usually not flashy; indeed, many choose them because they are not aesthetically distracting: if the keyboard has transparent switches or special keycaps, the dark FR4 plate remains neutral in the background. Since it is not metallic, it does not give reflections or colors, which can be a pro or con depending on your taste.
• Recommended combos: It is the wild card choice for those who want to play it safe. It works well with all types of switches: with linear it helps to get a fuller sound than aluminum, with tactile it maintains good feedback without stiffening too much. For modders, the FR4 is great for trying out particular cuts (e.g. half plates, additional holes) due to its low cost, so you can customize the feel. In gaming, an FR4 plate can be good if you don't want the total rigidity of metal but not too much flexibility either: it gives you moderate responsiveness and a non-intrusive sound. In short, if you are undecided and want a versatile plate that does not make mistakes, FR4 is a winning bet.
Polycarbonate (PC)
• Advantages: Polycarbonate is a rigid plastic but much more flexible than metal. It is appreciated for the soft and quiet typing it can offer. It's translucent, so ideal for RGB builds where the plate lets the backlight through. It also weighs very little. It is a perfect material for those who want to maximize typing comfort and a more muffled sound right out of the box, without complications.
• Sound profile: Soft and muffled. PC plates tend to dampen high sounds, producing a deeper thock and mute (attenuated) than metals. The sound of the keys is less metallic and more "plastic" in the good sense: duller and warmer. This makes them popular for getting quiet or low-sounding keyboards. A polycarbonate plate can make even noisy switches sound more subdued.
• Feel: Offers cushioned typing and slightly bouncy (bouncy). Pressing the keys on a PC plate feels a smoother bottom of the stroke, as if there were a slight spring: this is because the material flexes and absorbs part of the shock. The feeling is extremely comfortable, ideal for long writing sessions or for those who press hard and want to avoid hard impacts. Some describe it as typing on a cloud compared to the hardness of the metal.
• Stiffness/Flexibility: Very flexible. Among the common materials, polycarbonate is among the softest: it flexes visibly if you press in the center (especially on longer keyboards). This high flex means that the keyboard can bend slightly during use, increasing comfort. On the other hand, it loses rigidity: the switches will have an extra "play" thread until the plate stops them. In any case, it is perfect for those looking for maximum flexibility and do not mind a less firm feeling.
• Weight: Ultralight. PC is a lightweight plastic, so such a plate weighs a few grams. This reduces the total weight of the keyboard, which is useful if you move it around often. A lightweight plate, however, also means less mass to dampen vibrations, but for many the difference is minimal compared to the advantages.
• Aesthetics: Transparent or semi-transparent. PC plates are often clear, allowing you to see through the keyboard or spread the light from the LEDs evenly. This creates a nice effect with RGB, giving it a modern and high-tech look. Even without RGB, a transparent plate can make the PCB or other internal details stand out. But be careful: the PC can scratch more easily than metal, so it must be handled with care during assembly so as not to ruin the aesthetics.
• Recommended combos: Perfect for those who want a quiet and thocky keyboard. Paired with linear switches, polycarbonate enhances that deep, velvety sound that many love, making typing creamy. Indeed, there are those who suggest using PC plates only with linear ones because they "sound better" with those. With tactile or clicky switches it still works, but be aware that it will dampen both the sound and the feel of the bump a bit, so usually tactile purists prefer stiffer materials. For gaming, a PC plate offers maximum comfort but may be less responsive (due to the flex) in competitive games, it depends on taste, there are those who appreciate it anyway. In general, if you aim for comfort and a low sound, the PC in combination perhaps with gasket mounting will give you a keyboard as soft as butter.
POM (Polyoxymethylene)
• Advantages: POM is a type of plastic (also known as Delrin) used in plates for its unique properties: it is free-flowing, dense and has a controlled elasticity. It offers a soft typing experience similar to PC, but with greater consistency due to its density. The POM also has low friction, which means that switches mounted on a POM plate slide smoothly, useful for maximizing linear fluidity. In addition, it is relatively light and non-metallic (no rust, no oxidation).
• Sound profile: Deep and "creamy". POM plates are famous for producing a low, pleasant thock sound that is often described as creamy to the ear. They dampen metal vibrations well, making them quieter than metal plates. Compared to polycarbonate, POM has a slightly snappier sound (firm) but still muffled: it is slightly more resonant than PC, but still very far from the brilliance of aluminum or brass. In short, it gives the keyboard a full timbre but contained in the volume.
• Feeling: Soft and cushioned. Typing on a POM plate gives a soft, almost "gentle" feel on the fingers, with a slight elastic bounce. It is comparable to polycarbonate in flexibility, although some find POM even more cushioned at the bottom-out. In practice, it offers a bouncy feeling that makes writing very comfortable and quiet. Those who love silky linear keys often love the feel of POM because it accentuates linearity without noise or roughness.
• Stiffness/Flexibility: Flexible. Not as much as the most extreme PC, but it still flexes noticeably under pressure. It sits between PC and FR4 in terms of stiffness, giving just the right amount of compliance without feeling rubbery. The result is a plate with enough flex to reduce the impact on the fingers, but not so soft that it compromises the stability of the switches.
• Weight: Lightweight. POM is slightly denser than polycarbonate but remains a lightweight material compared to any metal. A POM plate adds little weight to the total, keeping the keyboard easy to handle. This lightness also contributes to the muffled sound (less mass that resonates).
• Aesthetics: POM plates are typically white or black. They have a matte and smooth appearance. If white, they can give a clean and original touch (semi-translucent, it lets in a little light); if black they look similar to the FR4 but without fiber texture. In both cases, the aesthetics are understated, no metallic colors or sheen. Note that POM, being plastic, can deform slightly with extreme heat, but in normal use this is not a problem.
• Recommended combos: Ideal for quiet linear builds. Many enthusiasts consider the POM to be the best plate for achieving a "creamy" thock sound with lubricated linear switches. The combined POM + linear switch produces a very full and not very metallic sound, and typing becomes buttery. If you are looking for a smooth and quiet keyboard for office or nighttime coding sessions, POM + linear + maybe sound-absorbing foam is the right combination. With tactile switches, the POM dampens feedback a bit (like the PC), so it's less used by fans of pure haptics, but there's nothing stopping you from trying it out if you want to tone down both the sound and the harshness of the bump. In gaming, a plate POM offers great comfort but less dry feedback: it is good for casual use and for those who prefer silence even while playing.
Stainless steel
• Advantages: Steel (stainless steel) is the hardest and strongest material available for plates. It is chosen when maximum structural stability is desired: a steel plate practically never flexes and makes the keyboard a single block. It is also very resistant to wear and corrosion (stainless steel does not rust). In the custom field it is not very common (due to its weight and extreme feel), but some appreciate it for particular builds or for its unbeatable solidity.
• Sound profile: Loud and ringing. Steel produces probably the loudest and highest-pitched sound of all common materials. Each press of the key is accompanied by a very pronounced, bright click, with clearly visible high frequencies. In addition, steel tends to resonate: if not properly dampened, it can have audible metal pings (being so rigid, it vibrates and propagates sound). The result is a very strong sound, which some find satisfying in gaming or with clicky, but can be too loud for others.
• Feel: Offers solid and straightforward typing. There is not the slightest yielding: when you press a key on a steel plate, the bottom of the stroke is as clear as a wall. The feedback is extremely solid and can help avoid accidental presses (you have to press with intention). However, the downside is that typing can be fatiguing if you type for a long time, given the total lack of cushioning. It's a feeling for those who want something relentless under their fingers.
• Stiffness/Flexibility: Maximum stiffness. Steel is even stiffer than brass. It practically never flexes during normal typing; Even when pressed hard, the plate remains flat and the buttons do not give way. This guarantees maximum mechanical precision (no unwanted movement), but zero elasticity.
• Weight: Very heavy. Stainless steel has a high density, so a steel plate adds a lot of weight to the fretboard (usually second only to brass, which has a similar weight). This can be good for having a keyboard that doesn't move an inch across your desk. On the other hand, it greatly increases the overall weight by making the keyboard less portable and eventually requiring sturdy non-slip feet.
• Aesthetics: Usually steel plates are silver-plated (polished or brushed steel) or painted. A polished steel plate can give a mirrored finish visible between the frets, for a very cool look, even if prone to fingerprints. When brushed, it has an industrial matte gray appearance. In any case, it gives an idea of visual solidity as well. It does not change color over time (stainless steel does not oxidize).
• Recommended pairings: Recommended almost exclusively for those who want the stiffest keyboard possible. In competitive gaming, some appreciate steel with linear switches, because the combination gives maximum immediacy and zero flexibility, every input is instantaneous, the keyboard feels like a solid extension of the hands. In addition, with clicky switches the steel amplifies the click making the keyboard very noisy: it can be fun for those who love the typewriter-like sound, but not very suitable in the office. In general, steel is for niches: for everyday use of writing it is not recommended (tiring and too loud), while for curious modders or for those who want to test the limits of rigidity it can be an interesting challenge. If you really want to use it, a tip is to combine it with soft mounts (gasket) and maybe add sound-absorbing foam to tame the beast a bit.
Carbon Fiber
• Advantages: Carbon fiber is an advanced composite material, known for its high strength and low weight. In plates, it offers a peculiar mix: it is almost as light as plastic, but can be almost as rigid as metal. The big advantage is therefore to get a robust keyboard but much lighter than using brass or steel. It also has an attractive technical appearance (woven black texture). It's a popular choice in builds where you want to reduce weight without sacrificing too much solidity.
• Sound Profile: Clear and clean. A carbon plate tends to produce a fairly bright and defined sound, but slightly less metallic than aluminum. In fact, the carbon dampens the metallic resonances a bit, giving a crisp but not too bright clack (sharp). Some call it a clean mid-high sound, with a hint more thock than alu, while others hear it similar to aluminum. In general, expect a balanced sound: not as gloomy as PC/POM, but not as resonant as steel either.
• Feel: Solid but with a touch of flexibility. Carbon fiber is extremely durable and, especially if the plate is ~1.5mm thick, offers a stiff and responsive typing (comparable to aluminum or more). However, many also report a slight spring effect thanks to the laminated structure of the carbon: in practice, the carbon plate can slightly flex under strong pressures, giving a minimum of elasticity. The feeling is therefore basically rigid, with firm feedback, but it can be less "cold" than steel. It is often described as moderate bouncy; it is a good compromise for those who want responsiveness with a touch of comfort.
• Stiffness/Flexibility: Rigid, but not extreme. In order of stiffness, carbon sits just below the densest metals. It is stiffer than POM and PC, and even a little more than aluminum for the same thickness, but generally slightly less rigid than brass or pure steel. Let's say that it provides excellent structural solidity with a much lower weight. In some builds it is considered a middle ground between the metal and plastic plates, combining characteristics of both.
• Weight: Very low. Lightness is one of the main reasons to choose carbon fiber. A carbon plate weighs very little, often less than an aluminum equivalent. This allows you to build lighter, more transportable keyboards without losing strength. The difference in weight is especially noticeable in large keyboards (e.g. full-size) where a metal plate would affect the final weight a lot.
• Aesthetics: It has a unique texture, black with a shiny weave pattern. If the plate is visible or partially visible, it gives a technical/modern look to the keyboard. Many transparent or semi-transparent homes voluntarily display carbon for aesthetic appeal. It should be noted that unlike metals, it cannot be anodized in various colors, it always remains black (unless surface painted). The surface is smooth but can fray on the edges if cut poorly, so it is important that it is of good quality.
• Recommended combos: Suitable for those who want a mix of responsiveness and portability. In gaming, a carbon plate is excellent: similar to aluminum in readiness but with the advantage of lightening the keyboard. With linear switches it returns a quick feel and a clear sound, without attenuating the high frequencies too much, so you may appreciate a clicky sound response but with a less metallic background. With tactile, it still provides solidity to feel the bump well. In general, it is an all-rounder choice for those who want to try something different from alu: versatile as a use (it is good for both writing and playing) but with its own personality. Just keep in mind that the quality of the carbon plate matters a lot (a cheap one might be more fragile), but a well-made one lasts a long time. It is often combined with both hard and soft mounts: on gasket mount it offers a light and slightly flexible keyboard, on top mount it guarantees solidity with low weight.
Final Comparison and Tips
We have seen how each material affects the character of a custom mechanical keyboard. In general, metals (aluminum, brass, steel) make the keyboard stiffer and more resonant, with higher and louder sounds, while plastic/composite materials (polycarbonate, POM, FR4, carbon) offer more flexibility and more muted and deep sounds. Which one to choose then? It depends on the use and personal preferences:
• If you play (gaming): a rather rigid plate is usually convenient for maximum responsiveness. Materials such as aluminum, carbon or brass keep the keyboard stable and responsive, useful in FPS or competitive games where you want immediate response to commands. Also, a rigid setup avoids too much flex that could disturb in fast actions. But watch out for the sound: if you play with high audio, it may not matter, but in silent aluminum/brass contexts they will sound loud. A common tip is to avoid excessively soft setups for gaming: for example, gasket mount + plate soft (PC/POM) could flex too much and give a "spongy" feel that is not suitable for fast gaming. Better a classic top mount or similar with a metal plate to keep everything in place. Of course, if your gaming is casual, you can also safely play on a soft keyboard, a matter of taste!
• If you write or program a lot: you will probably appreciate a plate that is more flexible and comfortable, less tiring on your fingers. In this case, polycarbonate or POM are great candidates for their soft typing and unobtrusive sound. After hours of typing, a slightly bouncy keyboard (gasket mount + plate PC for example) tires less than hammering on steel. The FR4 is also a great middle ground if you want some comfort without losing too much precision. The more muffled sound of these materials is also ideal for an office or studio environment, because it is less intrusive.
• Mixed Use and Modding: If you like to tinker and try out different setups, the FR4 is your best friend to start with. It's cheap, so you can have several and change plates to your keyboard to hear sound/feel differences without breaking the bank. In addition, its balanced profile gives you a neutral reference: you will better understand which direction to go (stiffer? try alu; softer? try PC, etc.). For mixed use (a little gaming, a little writing), aluminum remains a great all-round choice, balanced throughout. If, on the other hand, you want something special to show, you could opt for brass (for aesthetics and rich sound) or carbon (for modernity and lightness).
Combos to try: According to community recommendations, a couple of "classic" combos are: brass + tactile switches (to maximize feedback and tactile thock), polycarbonate / POM + linear switches (for quiet and buttery typing). If you use a gasket mount, a rigid plate such as aluminum or brass can compensate for the softness of the mount; conversely, on a hard top mount you may prefer a more yielding plate (PC, FR4) so as not to have a keyboard that is too "stone".
In conclusion, there is no absolute best material, each has pros and cons. The choice depends on what you are looking for: comfort and deep sound? Go to PC or POM. Precision and solid feel? Aluminum or brass for life. Middle ground? FR4 or carbon can give you a taste of both worlds. The important thing is to have fun customizing: if possible, try different plates and listen/hear how your keyboard changes. Even a simple plate change can transform the typing experience! We hope this comparison has cleared your mind and helped you choose the perfect plate for your next custom build. Happy searching and have fun!