Drawing the Traditional Acoustic Guitar Pickguard

Copyright © 2019 R.M. Mottola

[This article originally appeared in American Lutherie #141.]

The traditional steel string guitar pickguard has a distinctive and somewhat complex shape. Pre-made pickguards are readily available from lutherie suppliers for typical OM and dreadnought size guitars. I use these for instruments of these sizes when they also have traditional rosette patterns. But for other size guitars and for guitars that make use of non-traditional rosette patterns I will draw custom-size pickguard outlines fitted exactly to the instrument.

The step-by-step instructions here are for drawing using computer drawing software. Any program that has a reasonable collection of snaps; that can draw three point circular arcs; that can do fillets; and can make mirror copies of lines will work fine. All drawing programs that I know of can do all of these. Although I am not providing explicit instructions for drawing using paper, pencil, and compass, it should be readily apparent how the drawing can be made using these tools.

Figure 1 shows the area of the guitar top where the pickguard will go. The instrument in this drawing uses three concentric rosette rings. The pickguard drawing will be sized and fitted to the instrument. For me, the most important fitting operation is to size and locate the left side cut in the pickguard so that it is concentric with the soundhole and rosette rings and so that it evenly exposes or covers some of the rings.

In fig. 2 I’ve swung an arc in black to represent this edge of the pickguard, using the center point of the soundhole and a radius appropriate to expose just the inner rosette ring and to cover the two outer rings. This is unusual but it is done that way here just to demonstrate that it can be done. This arc can be drawn to expose or cover as much of the rosette as is desired.

I want the pickguard to sit evenly between the end of the fretboard and the top edge of the bridge. And I also want the left side edge to be just inboard of the low E string. The right side edge should be located so that it does not overlap any of the top purfling and so that it is approximately the same distance from the purfling as the left side soundhole cut is from the soundhole. All of these requirements are realized by drawing a construction line bounding box as shown in fig. 3.

The top side of the box as shown is drawn 0.25" (6.4mm) lower than the end of the fretboard and the bottom side of the box is drawn 0.25" (6.4mm) higher than the top edge of the bridge. In my own work these are the standard offsets I use but any reasonable offsets will work fine. The left side of the box is located just inside of the low E string. The strings are not shown in the drawing to keep the drawing simple. I find that simply offsetting the left side of the box 0.25" (6.4mm) toward the instrument centerline from the bottom right corner of the fretboard is a reasonable approximation. In the figure the inside edge of the top purfling is represented as a green line. The left side of the bounding box is located tangent to the waist part of the purfling edge. This is also an approximation that generally works out well for the finished pickguard drawing. A vertical centerline is also drawn for the bounding box. Also note that I’ve eliminated the rosette rings in fig. 3 and in subsequent figures just to make the figures a bit less busy.

Construction lines that will be used to draw the left side and bottom of the pickguard are added in fig. 4. A line is added 0.125" (3.2mm) inside from the left side of the box. Two lines are added inside from the bottom of the box. The first is 0.125" (3.2mm) from the bottom and the second is 0.125" (3.2mm) from the first. These construction lines are used to draw three point arcs for the left side and bottom of the pickguard. Note that these offset values will result in a traditional shape but other values can be used.

The intersections of the construction lines at the bottom with the bounding box sides and centerline are used to draw two three point arcs, as shown in fig. 5. In most implementations of the conventional pickguard shape that I’ve seen, the bottom is composed of two tangent arcs. These are implemented by trimming off (erasing) the left side of the lower arc and the right side of the upper arc. Results are shown in fig. 6.

The left side of the pickguard is drawn next. A short construction line is drawn from the intersection of the pickguard bottom and the left side inner construction line, to and perpendicular to the left side of the box. A similar construction line is drawn from the intersection of the pickguard soundhole arc and the left side inner construction line.

Then a three point arc is drawn as shown in fig. 7. The curve of the right side of the pickguard is drawn by mirroring the left side curve about the box centerline (fig. 8).

The very top of the pickguard outline is a large radius curve. I draw this using the bottom left corner of the bounding box as the center, and swing an arc from the intersection of the pickguard soundhole arc and the top of the box, toward the right side of the box. See fig. 9.

Now the right side of the outline is continued by extending the current arc down to the bottom of the outline and up to the top arc of the outline. (fig. 10).

At this point I’ll take a look at how close the right side of the pickguard comes to the purfling. It will never be too close but sometimes I will want it to be a bit closer than it is. In that case the right side arc is just moved to the right as much as is needed. Doing so will disconnect it from the bottom arc, so then extend the bottom arc to meet the right side.

The construction lines are no longer needed so these have been eliminated in fig. 11.

The line ends are all trimmed as needed, shown in fig. 12. The final step in the drawing process is filleting (rounding over) some of the sharp intersections of the arcs. The points at both ends of the soundhole arc are essentially left alone, but the rest are rounded over to some extent. How much to round over is a matter of taste, but traditional results can be had by rounding over the bottom corners with a 1" (25.4mm) radius, and rounding over the top intersection using a 2" (50.8mm) radius.

Fig. 13 shows the fillets and in fig. 14 the rosette lines have been added so you can see the final effect.