The following is excerpted from “With All the Precision Possible: Roubo on Furniture,” by André-Jacob Roubo, translated by Don Williams, Michele Pietryka-Pagán and Philippe Lafargue. In addition to the translated text and images from the original 18th-centry masterpiece, “With All the Precision Possible: Roubo on Furniture” also includes five contemporary essays on Roubo’s writing by craftsmen Christopher Schwarz, Don Williams, Michael Mascelli, Philippe Lafargue and Jonathan Thornton.
After you have determined the measurements of the work that you wish to make, you draw it on a straight and uniform board. This is what woodworkers call marking the work on the plan. In general, they call the plan all the cuts of the work both in height and width, which represent the shapes [profiles] of all the parts that make it up, or to speak more intelligibly, represent the shape of the wood, its thickness and its width. [It is essentially a layout and cutting list.]
Before beginning to draw the work on the plan, one must determine the width of the sides, the thickness of the wood, the width and the form of the contours, which you do on paper so as to master all the changes or other additions that you judge appropriate. [The implication is clearly that at least some portion of the drawing is at full scale.] This is much better than designing the shapes [profiles] on the plan, because not only are they never as good as on the paper, but because it is lost time that you use to draw the shapes [profiles] at all the places where they are found on this same plan. When the work is of a certain prominence, it is good to make a design of it on paper before laying it out, because you can better make an account of the forms and of the harmony all the parts have with each other.
When the work is particularly considerable, both for its richness as for its size, you must not be content with one design. It is necessary to draw it life-size on the walls of the room in which it will be installed so that you can judge the effect of the entire composition, including both joinery and Carving.
When the nature of the work is out of the ordinary you should make small models of it so as to neglect nothing in making it perfect.
I will not deny that all these precautions are costly, but they accelerate the execution of the work by removing all the difficulties that could be encountered. What’s more, they [the added precautions] respond with success. Whatever experience you have, it often happens that during the execution some difficulties arise that you never thought of. That is why they say to never be too enamored with your theory by avoiding your drawings and models. What’s more, what I recommend here is nothing new, since the greatest Artists of all kinds never execute anything they have not drawn and modeled previously.
The work thus designed or modeled according to the occasion, you draw on the board, which is ordinarily of pine and dressed [trimmed and whitewashed evenly] so as to be able to draw the work neatly. That is why we prefer this wood to all others for this use because when it is of a good quality it is extremely soft and [of] an even hardness throughout.
We use black or red stone, which we call sanguine [reddish drawing chalk], for drawing the work. However, it is good to begin to draw it with chalk because it erases more easily than black or red stone, which you should not use except when you have it all drawn with chalk.
You should not draw the shapes [profiles], as I said above, you must [instead] only do a chamfer/bevel [that is] the width of the moulding, but you must make one edge of the mouldings square while the other is contoured. However, as joinery can be simple, either with moulding part of the frame or moulding exceeding the thickness of the frame, it is good to draw the bulk of the shape [profile] of each type in a different manner, so the worker who makes the work cannot be deceived.
Simple profiles are designed with a single chamfer, like that of side g, Fig. 4. Those where the moulding is part of the thickness of the frame have a small framework [next to] a chamfer similar to the first one, with the exception that it is notched/squared by about a line down from the face corner, like that of side h.
For those of a large framework where the moulding exceeds the thickness of the frame, you make a chamfer in the front, and at the rear you mark their projection on the edges, noting to mark the grooves. When the frameworks have a moulding at the rear, you make a little chamfer to indicate this. Look at profile, side i, which represents a shape [profile] of a moulding projecting on one side, and level with the frame on the other. Side l represents a tongue-and-groove framework where the side enters by tongue and groove into a door frame.
In general, you must take care to draw the work precisely so that whoever makes it can do it more easily and can even trace on [top of] the plan without making other divisions.(4) [In order to design a space’s accouterments such as paneling, windows and doors en toto, one has to divide the expanse of the room into sections to lay out correctly and harmoniously the paneling including the frame work. As the portions of design are assembled into a compiled whole, the risk of compounding any error is substantial. In this passage, Roubo is sternly warning against sloppy layout. When the assembled plan is correct you can then project the same layout onto the wall and cut all your pieces. If the craftsmen doubt the accuracy of the drawing or note an error, they must restart with each portion or restart the layout to fit the wall correctly.] That is why one must trace with a sharpened point all the widths of the frames and the mouldings, which is more accurate than tracing with white stone. One must also take care to mark precisely all the grooves and rabbets, as well as tongues and grooves, the middles as well as the angles, that one must number, so that you can see in a single glance all the parts which go with the others.
The door frames are also marked in bulk, noting only to mark exactly the place of the grooves and the depth of the rabbet. Look at Fig. 5, which represents some paneling marked both in width and height.
The profiles of casements are also marked in bulk. Their little wooden pieces are marked squarely according to their width and thickness. When they are little uprights, you mark them with a cross, which passes the four angles, which indicates their cut with a diamond point. You also draw the rabbet of the frame with glass, as well as the shape of the profile of the imposts [fan lights], those of the door handle/hardware, and of the hand rail, see Fig. 6.
It is good before drawing the work, especially when you have not drawn anything, to calculate all the width of the wood so as to see right away the size of the panels or pilasters that you want to mark, so as to decrease or increase their number.
This way is the surest and easiest, not only because you make mistakes less easily, but also because it shortens the time that you are often required to spend making divisions and erasing them.
Joiners also draw the elevation of their works, especially when it is curved or ornamented with carving. These elevations are made with a sharp point without any shadow, if you omit the ornaments. But the latter are not the work of joiners. These elevations are called plans, in workmen’s terms, and are marked on large panels of pine. As it happens that there are lines which are only for construction, that is to say, to design some joints or some assemblies, you make them of another color than those of the elevation, so as to distinguish them. That is to say, that if the elevation is marked in black, the construction lines are made in red. Sometimes these lines are marked only by a point, especially when it is absolutely necessary that they be perfectly straight.
(4) While I say here that you must draw the work exactly on the plan so that you can trace on top of it, it is good that the workers take the pain to verify if the sections are made correctly when they start to trace so as to avoid following mistakes which may be on the plan, supposing there are any. What’s more, the divisions are always subject to some errors. That is why it is good to re-draw them on the work itself, in spite of the exactness of the plan [replicating the layout on the workpiece].