This is an excerpt from “Roubo on Marquetry” by André-Jacob Roubo; translation by Donald C. Williams, Michele Pietryka-Pagán & Philippe Lafargue.
Cabinetry panels are ordinarily surrounded by friezes, whether of the same wood oriented in different directions, or in compositions, which is the same thing; in one or the other case, one sometimes puts banding of different colors, surrounded by stringwork, as I have already said. These bandings form a second frame around the panel, the four angles of which one makes various crossovers [where the banding crosses over itself at 90°], as represented in Figs. 1, 2 and 3, which are positioned in the same manner, although different in form, one from the other.
Whether the bandings are simple, as in Figs. 2 and 3, or they are doubled, as in Figure 1, it is always necessary that they be surrounded by stringwork, which separates them from the rest of the work, which is a general rule in all cases. This stringwork is ordinarily white; however, one can make them of other colors, which is not important, provided that their color makes a break with the woods that separate them, and that they be of a wood very exible [pliable] and along the grain, so as to be able to work them very easily, as I will teach in a moment. See Fig. 4, which represents a banding with its two strings, which are glued there, showing as much of the face as the side.
When the colors of the frieze are very different from that of the panels, it happens that the stringwork does not distinguish enough from one or the other color, which obliges putting a double stringwork of two different colors, which are in opposition with the background of the work, which is a different color. Look at Fig. 5, which represents stringwork of five types, namely a double stringwork, side A–B; a triple stringwork, of which the middle is black, side C; another triple stringwork of which the middle is white, side D; a triple stringwork of which the middle is half black and white, side E; finally another type of triple stringwork, of which the three parts that make it are all half-colors, and in opposition one to the other, side F.
Friezes are sometimes made of sections with woods of different colors, which form simple frames, or are filled in across their whole width, by whichever composition. The first way to make friezes, represented in Figs. 6 and 7, is the simplest, and does not require any more care than to trace regular circles or lozenges, whether these friezes be without bandings, as in Fig. 6, or with bandings, as in Fig. 7.
The second way to fill in the interior of friezes is much more complicated than the first, because the space of these last ones being ordinarily limited, the parts that compose the composition of which they are filled in can only be very small. This makes their perfect execution very difficult, especially since one normally puts Greek keys or broken bands there, which are comprised of a large number of different small pieces, as one can see in Figs. 8, 9, 10, 11 and 12.
The Greek keys or broken bands, represented in these different figures, are more or less composed according to the size of the friezes, and are traced in the same manner, as I am going to explain.
When one wishes to trace this sort of ornament, it is necessary first of all, after having traced the middle of the frieze, as line a–b, Fig. 8, to divide the width of the frieze in as many equal parts as the composition requires, seven being the number in this figure [the filled being equal to the empty; in other words, there is balance between the positive and negative space]. This being done, one traces as many parallel lines as there are points in the given division; then one traces these same spaces or divisions perpendicularly, observing that one finds one in the middle of the work, as in this figure; after which one determines the shape of the broken bands, to which one makes as many turns as are necessary to fill in the length of the frieze, observing that at the end, one has made an entire revolution, or at least a happy ending, without having seemed to have been cut, as I had to do in Fig. 8, side G; in that of Fig. 9, side H; that of Fig. 10, side I, and that of Fig. 11, side L.
One inconvenient observation is that if the width of the frieze is bordered, its length cannot be made until after dividing this same width in as many pieces as one judges appropriate, as one could see above. If, on the contrary, it is the length of the frieze that is given, as happens ordinarily, one cannot determine the width until after having made the choice of composition that one wants to use, and of the number of turns that half of the length of the frieze could contain, which will give a number of whichever parts, on which one divides the middle of the length of the frieze, observing still to put one of these divisions in the middle of the length. The division of the length of the frieze once made, one will easily have the width, since the division is already made, repeated as many times as necessary, according to the adopted composition that is given.
What I just said touching on the division of Fig. 8 is applicable to all the others of such types as they can be; that is why I do not speak any further of this, given that only an inspection of the figures can, and even should suffice, for as much as one wishes to pay attention.
Figure 12 represents a type of composition appropriate for filling boxes or squared sections, separated one from the others, as is found sometimes, especially in the corners of friezes, where they can take the place of rosettes or other ornaments.
— Meghan Bates