Lost Art Press

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Roubo on Upholstery

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Uphostery-1
Classic un-sprung French arm chair with loose cushion.


This is an excerpt from “With All the Precision Possible: Roubo on Furniture” by André-Jacob Roubo;  translation by Donald C. Williams, Michele Pietryka-Pagán & Philippe Lafargue. 

So Roubo could not very well do a comprehensive book on furniture making without including some mention of how to prepare frames for upholstery, and yet in his opening line he gives a real clue as to his general feelings about the matter. He says, “…seats in general are finished with fabric or caning…where the former is the most utilized and totally the province of the upholsterer.” It is not difficult to imagine Roubo arguing with an irate upholsterer over the details of a frame, just the way that modern upholsterers complain about the placement of tacking rails, and in the end just let the upholsterer figure out how to complete the chair. Roubo is clear on how to prepare loose or “slip” seats, those that are removable from the chair, but when he discusses how upholstery materials are permanently attached, it was just not so.

Upholstery-2
Figures 7, 8 & 9 from Plate 227

In Plate 227 Roubo provides three figures in profile of the attachment of webbing to massive carved frames, these are figures 7, 8 & 9. Upon first seeing this plate, my reaction was simply, “Impossible!” But knowing Roubo’s meticulous drawing skill and thorough work, there had to be an answer.

Figure 8 clearly shows (from left) the webbing attached to the side of the rail, tacked near the top, a next layer of under upholstery (muslin) tacked below that, and finally a show cover attached with decorative tacks right at the top of the decorative moulding. As a student of the English tradition of upholstery, this was unfamiliar to me, as the English securely tack the webbing to the top of the frame (as shown in Figure 7) and thereby have good access to stretch or “strain” it tight. So then why is Roubo showing the webbing in Figure 8 this way? I put this question to everyone I thought could help until I was fortunate to meet the gifted, classically trained and very French master upholsterer Bruno Paulin-Lopez. Interestingly, Roubo, was not required reading for his training, though he was familiar with the well-known and contemporary book on the trades by Denis Diderot, and another massive text called Tapisseire D’Ameublement by Claude Ossut (not translated into English), both of which explain in quite some detail how to web a chair frame.

First and foremost, the French tradition of webbing requires the webs to be placed tight, side by side with no gaps, unlike the English, which employs an open weave pattern, and this is critical to understanding what Roubo is portraying. And secondly, this type of un-sprung upholstery (chair, ottoman, chaise, etc.) would have a considerable, in some cases massive, pillow on top of the webbed “deck.” Finally, Roubo, seemingly aware that he is not being clear, gives us some information in a long footnote. To paraphrase, “…most upholsterers feel that the webbing should be on the side, while others are convinced that it could be on the top of the frame, which would make it very firm.”

With Bruno’s guidance, I have come to believe that the “most upholsterers” Roubo consulted were the older generation who grew up tacking everything on the side of the rails and whom Roubo did not dare slight in his representation of how this should be done. And the “others” are those talented pioneers desperately trying to make sure their upholstery methods could keep up with the fast-changing furniture styles of the opulent French court, such as the elegant gentleman craftsman portrayed by Diderot.

The following is a recreation to scale of Figure 8 and shows an interpretation of how the webbing would have been placed unfolded on the rabbeted edge, followed by a muslin layer tacked slightly above, and finally the show cover tacked right at the edge with decorative tacks. Because the webbing is side by side, there is a smooth surface for the succeeding layers, and because the piece is un-sprung it would not be necessary to stretch the webbing as tightly, and would actually give the bottom of the pillow a place to nestle.

Upholstery3
The webbing shown here and in the next image is a modern reproduction, for illustration purposes only.

The next recreation uses the same frame pattern and shows a more “modern” approach with webbing folded under, tacked on top of the rail, followed by a layer of linen hessian tacked on a beveled edge to save the space on the front of the rail for the tacking of the show cover. This technique is similar to the English style.

Upholstery-4

The final recreation shows a full hand-sewn foundation using a coarse “first stuffing” material, which is drawn by careful stitching to form a firm seat and a rolled edge. This technique evolved in both the French and English traditions, and creates a custom, extremely durable base for a softer second stuffing and made possible the upholstery of many complex furniture designs.

Upholstery-5

I feel confident in saying that Roubo would be truly pleased to know that the techniques he illustrated as well as their many variations are still practiced by the finest upholsterers working today.  — Michael Mascelli

— MB

Designing with Ornament

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By-HAND-and-Eye3


This is an excerpt from “By Hand and Eye” by Geo. R. Walker and Jim Tolpin. 

“[Architectural ornamentation] liberates us from the tyranny of the useful and satisfies our need for harmony.” — Roger Scruton

By-HAND-and-Eye2
The subtle
carving on this table
leg accomplishes
several things at once.
It highlights the form,
provides interest for a
close view and emphasizes
this object’s
place of importance in
the life of a home.

Traditionally, ornament and mouldings were employed to punctuate and emphasize a form. Even though they’ve been overdone, it doesn’t mean they don’t have a valid place. Our woodworking design tradition has seen wide swings in taste concerning ornament, embellishment and mouldings. Some periods drip with overcooked gingerbread, some scrape clean down to the bone. A few contemporary designers even abhor figured wood, and some modernist designers dictated that ornament should be allowed only if it looked machine made – no hints of man’s hand. It’s difficult today, with the pendulum swung away from traditional ornament, to see how it was originally viewed, especially when bursts of excess litter our furniture history. It might be helpful to understand the original craft intent and not simply write off traditional ornament and mouldings as a relic of another era. Ornament must complete a design – similar to the effect of leaves on a tree or feathers on a bird. It’s not an add-on, it’s not a strategy to rescue an inferior design. Abraham Swan (circa 1757) wrote, “If the original design be bad, superadded ornaments will make the whole appear like a clown in a laced waistcoat.”

The bones underneath must be good or ornament will only make the whole design worse. That’s the reason so much mass-produced 20th-century Colonial-style furniture fails so pointedly.

By-HAND-and-Eye

Ornament and mouldings must have a function. While we think today of function as primarily a structural element (a way to meet a physical requirement), the craft idea of function was much broader, because the definition of function included visual appearance. Mouldings or other ornaments were used to emphasize a form, create a visual border, transition one part to the next or to create layers of interest on different scales (such as a close view). Another function of ornament is to set something apart. As reflected in Swan’s quotation above, this human need to embellish what we value is the reason that even our ancestors of modest means felt compelled to use ornament to decorate a powder horn, dowry chest or quilt. The question to ask is not whether the ornament or moulding adds to the design, but whether the design lacks something without it.

— Meghan B.

Drawing the Acanthus Leaf

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Drawing-1This is an excerpt from “Carving the Acanthus Leaf” by Mary May.

DRAWING THE SYMMETRICAL ‘S’ CURVE
This example works with multiple curves and shows how to draw a symmetrical design that identifies the midrib of the leaf for Chapter 5. By using a compass and a horizontal line divided into eight segments, a slow, gentle “S” curve (also referred to as a cyma curve) can easily be drawn.

• Draw a horizontal line and divide it into eight equal segments.

• Set your compass to Length A (four segments).

• Position the compass point on Compass Point 1 and strike a mark above the line as shown.

• Position the compass point on Compass Point 2 and strike another mark above the line, creating Compass Point 4 where the lines intersect.

• Place the compass point at Compass Point 4 and draw an arc intersecting the horizontal line at Compass Point 1 and also Compass Point 2.

• Notice that the distance between Compass Point 1 and Compass Point 2 is only three  segments, thereby causing the arc to become slower, or more open.

• Position the compass point on Compass Point 2 and strike a mark below the line as shown.

• Position the compass point on Compass Point 3 and strike a mark creating Compass Point 5 where the lines intersect.

• Place the compass point at Compass Point 5 and draw an arc intersecting the horizontal line at Compass Point 2 and also Compass Point 3.

Drawing-2

DRAWING A SPIRAL
Now let’s draw a more challenging curve – the spiral, scroll or volute. Many acanthus leaves terminate with a spiral shape at the base of the leaf, while other designs have entire leaves curling in the shape of a spiral.

This process shows the technique of drawing a basic spiral using straight lines and a compass.

• Draw a vertical and horizontal line with a small square at the intersection. The larger the square, the more open the spiral; the smaller the square, the tighter the spiral.

• Begin by placing the compass point at the upper right corner of the small square and strike a curve in only the upper left quadrant. The size is your choice – try experimenting with various sizes.

• Moving counterclockwise around the small center square, reposition the compass point to the upper left of the square and strike a curve in the lower left corner, beginning and connecting with the end of previous curve.

• Continue repositioning the compass point counter-clockwise around the small, center square and repeat the steps above, forming a continuous spiraling line.

Drawing-3
The illustration above shows an incorrect flow of a spiral, a correct flow using the compass method  shown and the completed drawing of the Baroque style leaf based on the curves drawn (Chapter 16). Notice how your eye is invited to follow along the gentle curves of the correctly flowing line, where the incorrect lines are jarring and uncomfortable to view. The lines represent the approximate center of the leaf. Notice the line that joins the two scrolls is drawn freehand and should appear to be flowing  directly from the top scroll as shown.

— Meghan B.

Slöjd Bowl and Trough

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Bowl-1

This is an excerpt from “Slöjd in Wood” by Jögge Sundqvist.

Traditionally, households needed to be self-sufficient and had to make all kinds of everyday objects. There were many kinds of hewn bowls and troughs for baking, meat preparation, milk production and fermented drinks. They were made from a green blank from a tree trunk. The trunk was cut and split lengthwise into a half, then hollowed out from the heartwood side. Because these containers are exposed to moisture, the design incorporates strength and durability. The walls at each end of the trough must be three times thicker than the wood along the sides. The handles are placed at the ends of the blank.

I have learned another way of doing this from the legendary woodworker Bengt Lidström, who made beautiful bird bowls. He worked from either the heartwood side or from the bark side. Both methods are described in this chapter.

Bowl-5

Tools. Chopping block, froe, wooden maul, axe, shaving horse, drawknife, adze, workbench, scrub plane, spokeshave, Japanese saw, sheath knife, long bent gouge (#8, 35mm), spoon gouge (#9, 13mm), ruler, pencil, folding ruler, screw clamp, chip carving knife, paintbrush.

Material. Straight-grained, knot-free deciduous wood such as aspen, alder or birch, wood glue, raw coldpressed linseed oil, and artist’s oil paint.

PREPARING THE BLANK
Choose a straight-grained, knot-free piece. Trim to about 10cm (3-15/16″) longer than the bowl you want to make. When a tree is felled, the pith always has a crack that begins in the end grain. When you split the blank, line up the froe blade with this felling crack.

Hew away about 1cm (3/8″) of the juvenile wood nearest the pith. While hewing, sight along the edge of the blank’s end-grain face as a reference for a flat surface.

If you are hollowing from the bark side of the log, further flatten the heartwood side so the blank sits steady on the bench. Use either a plane at the workbench or a drawknife at the shaving horse. Remove the bark with a drawknife.

Lay out centerlines on the bowl face. Transfer the lines to all four faces. Now lay out the shape of the bowl using the centerlines to guide the shape. Make sure there is 2cm to 3cm (13/16″ to 1-3/16″) extra material on both ends to fasten the blank on the workbench.

You will use a lot of force during hollowing, so it is important to clamp the blank firmly to your workbench. Now hollow out the blank with an adze.

To quickly remove material on the bark side, you can first use a thin, straight-beveled axe to cut off the upper layer. You can also use a bowsaw to make multiple depth cuts to allow the waste to chip out more easily.

HOLLOWING OUT
Use an adze for hollowing out the blank. The adze has a bevel on the outside, which in combination with the short handle creates an arc when you cut. Lock your elbows to the sides of your body. Place the other hand around your wrist for control and accuracy. Holding the adze at the farthest end of the handle, drive it into the wood vigorously to make depth cuts into the surface. Start from the middle of the hole and work toward the ends.

Like hewing with an axe, you now change the angle of the cut to clear away the waste.

Turn the piece and refasten it if it is difficult to cut from the other side. Use your body to change the cutting angle as you follow the shape.

You can also use a mallet and a long bent gouge (No. 8L, 35mm) to start cutting in the middle of the bowl. To begin hollowing, it is easiest to cut across the fibers. Keep in mind that cutting the fibers across the grain doesn’t leave as smooth a surface as cutting with the grain.

For controlled cuts, place your left hand on the gouge handle just above the tool edge and use your wrist as a brake as you press it against the blank.

With your right hand against the end of the handle and supported by your chest, push the gouge forward by leaning into the cut. Use steady pressure to get long, even and controlled cuts.

This technique is particularly useful in the bottom when you cut near the cross-grain wood, where the fibers meet each other. The left hand acts as a control for both speed and depth of cut.

Bowl-6

The narrow ends of the bowl are thicker and angled toward the bottom, making the end-grain fibers longer and therefore stronger.

Smooth the rim along the top of the bowl. At this stage, it is necessary to refine the form by marking new lines.

Check the level of the sides of the bowl by laying a straight edge across the top.

Measure for even thickness along the bottom by using a ruler to compare the height of the sides versus the depth of the bowl.

The fibers rise a little after drying. Remember to clean-cut the bowl when it is dry for a smoother surface. For a bowl 40cm (15-3/4″) long, I suggest a final thickness of 8mm (5/16″) along the sides and bottom, and about 20mm (13/16″) in the end-grain wood. If there is tear-out in cross-grain wood, you will need to carefully make the final clean cut at a 90 degree angle to the fiber direction.

— MB

What Happens Inside a Mortise and Tenon Joint?

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This is an excerpt from “The Woodworker: The Charles H. Hayward Years: Volume III” published by Lost Art Press.

Readers will recall that in January WOODWORKER we gave on page 8 an article “Wedging Mortise and Tenon Joints.” The following letter is from a reader who does not agree with the view expressed in it, and we publish it here as the subject is of considerable interest. Possibly readers may have other opinions about it, and if so we should welcome correspondence.

If your contributor would conduct the following experiment, he might be induced to modify his views concerning the gluing of a mortise and tenon joint as described in his article in last month’s WOODWORKER. Cut two or three inches from the end of a wide board. Repeat this, so that there are two pieces of exactly the same width and of a similar texture. Mark the width exactly on a board and soak both pieces in water until saturated. Measure this against the previous width. The wood will have expanded to a degree depending on its original water content.

The-Woodworker-Vol-3
AN INTERESTING EXPERIMENT IN SHRINKAGE Piece A is cramped at ends only, centre remaining free. At B cramps are fixed along the width.

Fix piece A firmly down on a board with handscrews at each end so that, although the centre is loose, the extreme edges cannot move during drying. Fix piece B to a board with handscrews all along its width so that it cannont move at any point during drying. Place both pieces in a warm atmosphere and leave to dry. In the process of drying piece A will split, but piece B will dry out without shrinkage, and will retain its new width permanently. Contrary to what might be expected, it will also be largely unaffected by small atmospheric changes. The cells of the wood seem to be permanently stretched. This experiment proves that wood will be largely impervious to atmospheric changes and will lose its customary tendency to shrink or swell, if it is held at every point.

To turn to the mortise and tenon joint, it will now be appreciated that if the whole of the sides of the tenon and the sides of the mortise are in contact and are glued, no shrinkage can take place at these points. It also follows that if part of the tenon and mortise is unglued, shrinkage and consequent movement will take place in the unglued portion, while the glued portion will remain stable if it can withstand the pull of the unglued portion so close to it. So far as strength alone is concerned, it is obvious that a completely glued joint must be stronger than one partly glued.

The conclusion seem to be: That there would be a loss of strength in a joint only partly glued.

That the unglued portion puts an added strain on the glued portion.

That a joint properly fitted and glued will not move at the shoulder any more than any other part of the joint.

— Meghan B.