Fretboard inlays are one of the most personal touches you can add to a guitar. Whether you are fitting simple dot markers or intricate custom designs in mother of pearl, the process follows the same fundamental steps — cut your inlay material to shape, rout a matching cavity in the fretboard, glue the inlay in place, and level everything flush. Here is how to do each stage well.
Inlay materials
Mother of pearl is the classic choice for guitar inlays. White pearl gives a clean, traditional look while abalone adds iridescent colour that shifts with the light. Both are natural shell materials — they cut and shape well but produce fine dust that you should avoid breathing (always wear a dust mask when working with shell).
Reconstituted stone is an increasingly popular alternative. It is more consistent than natural shell, available in a wider range of colours, and easier to cut cleanly. It is also significantly less expensive for large inlays. Pre-cut inlay shapes in standard dot, block, trapezoid and custom designs can save considerable time if they match what you need.
Other materials used for inlays include bone, brass, wood (contrasting species), acrylic, and Luminlay (a phosphorescent material that glows in the dark, popular for side dots on stage guitars).
Cutting your own inlay shapes
If you are cutting custom shapes, you will need a jeweller's saw with fine blades (2/0 or 4/0), a small bench pin, and a lot of patience. Print or draw your design on paper, glue it temporarily to the shell blank with a light adhesive (rubber cement or repositionable spray adhesive), and cut along the lines with steady, controlled strokes. Let the saw do the work — pearl and abalone are brittle and will crack if you force the blade or try to turn too sharply.
For straight-sided shapes like blocks and parallelograms, a small disc sander or a flat file gives cleaner edges than a saw. Sand right up to your line and check the shape against your template frequently. The inlay does not need to be perfect — you will be routing a cavity to match it, and any small gaps get filled with tinted epoxy — but the closer the fit, the cleaner the final result.
Routing the cavity
Place your finished inlay piece on the fretboard exactly where you want it and trace around it with a sharp scribe or craft knife. Score the outline firmly — you want a clear, visible line to follow. Some builders darken the scribed line with a pencil to make it easier to see on dark fretboard woods like ebony or rosewood.
Rout the cavity using a Dremel or small rotary tool with a 1mm or 1.5mm straight bit. Set the depth to match the thickness of your inlay minus about 0.3mm — the inlay should sit very slightly proud so you can sand it flush without going below the fretboard surface. Work from the centre outward, clearing the bulk of the waste first, then carefully approaching the scribed outline. Stay about 0.5mm inside the line with the rotary tool and finish the edges with a sharp chisel, paring right up to the scribed line.
Test-fit the inlay frequently. It should drop into the cavity with minimal force — if you need to press hard, the cavity is too tight somewhere. It is much easier to enlarge the cavity slightly than to fill a gap, so err on the side of a snug fit.
Gluing
The standard adhesive for fretboard inlays is two-part epoxy mixed with fine dust to match the fretboard colour. For ebony fretboards, mix the epoxy with ebony sanding dust or a small amount of black pigment. For rosewood, use rosewood dust or a dark brown pigment. The tinted epoxy fills any tiny gaps between the inlay and the cavity walls, making the joint nearly invisible.
Apply the tinted epoxy to the cavity (not the inlay — you want it in the hole, not squeezed out around the edges), press the inlay into place, and clamp it flat with a small caul and clamp. Wipe away any squeeze-out immediately with a scraper or the edge of a credit card. If epoxy does squeeze out onto the fretboard surface, do not try to wipe it — you will smear it into the grain. Let it cure fully and scrape it off cleanly.
Some builders prefer CA (cyanoacrylate) adhesive instead of epoxy. CA sets faster and is easier to sand, but it does not fill gaps as well and the bond is more brittle. For well-fitting inlays, CA works perfectly. For looser fits, epoxy is more forgiving.
Levelling and finishing
Once the adhesive has fully cured (24 hours for epoxy, 1-2 hours for CA), level the inlay flush with the fretboard surface. Start with a flat sanding block and 220-grit paper, working evenly across the inlay and the surrounding fretboard. Progress through 320, 400 and 600 grit until the inlay and fretboard are perfectly flush with no visible lip.
At this stage, pearl and abalone inlays will look dull and scratched — this is normal. Their lustre comes back when you continue sanding through finer grits (800, 1000, 1500) or when the fretboard receives its finish. If you are applying an oil finish to the fretboard, the oil will bring out the shell's natural iridescence beautifully. If the fretboard will be left unfinished (as most ebony and rosewood boards are), you can buff the inlays individually with a fine polishing compound on a cloth to bring up their shine without affecting the surrounding wood.
Side dots
Side dots are the small position markers on the edge of the fretboard that the player sees from above while playing. They are typically 2mm or 2.5mm diameter dots of pearl, plastic, or Luminlay. Drill the holes with a brad-point bit matched exactly to your dot diameter, apply a drop of CA adhesive, press the dot in, and sand flush once cured. Side dots go at the same fret positions as your face inlays — 3rd, 5th, 7th, 9th, 12th (double dot), 15th, 17th, 19th and 21st frets.
