Don’t Wash … Scour!

Last summer I recorded my investigations into replicating early 19th century book cloth  using XSL pigments. One difficulty was achieving an even coloring, and several commenters indicated I should scour the fabric, rather than just wash it. Finally, I had a little time to try this, and although I haven’t had a chance to do more dying, tests with wheat starch paste have been astounding.

Note all the yellowish junk that came out of the muslin: oils, waxes, and pectic substances.

I boiled 1.5 yards of Springs Creative 45″ unbleached muslin (133 x 72 thread count, .007″ thick, $4.00 a yard) for two hours in a stainless steel pot, using 1 tablespoon of soda ash per 6 cups of water. Since it smells a bit, it is advisable to have a externally vented exhaust hood.  A long stirring stick is necessary, as are rubber gloves.

Keep a close eye on the boiling muslin. I used large pieces of cloth, for future use as covering material. As the water boils, hot areas form bubbles under folded and wrinkled areas. Then when you stir, they get released and the pot bubbles over, or worse, spills on you. I stirred the pot every 15 minutes so that all cloth surfaces were exposed to the scouring, and adjusted the temperature as necessary to keep an even boil.

The scouring raised the pH of the cloth from around 5 to 7, though this was measured with testing strips and is likely not super accurate. Soda ash is around 10 or 11 pH. The scouring removed oils, waxes, and pectic substances. The cotton fibers swelled and softened during the process.

Muslin samples pasted onto Mohawk Superfine. Left: Scoured. Middle: Washed. Right: Untreated. Note the superior adhesion of the scoured sample, skinning the paper during a pull test.

The difference in adhesion between the scoured, washed, and untreated samples is remarkable. All were pasted with Aytex P wheat starch paste onto a piece of Mohawk Superfine, with the same weight during drying.  I testing the adhesive strength by pulling the fabric away from the paper at 180 degrees. The scoured sample delaminated the paper, while the washed sample (hot water, a tiny bit of Seventh Generation Free and Clear detergent, industrial washing machine) and untreated sample released without affecting the surface of the paper. I tried this two more times, and the results were the same. In a separate test using EVA all the samples delaminated the paper.  I’d like to get a push-pull gauge to quantify the adhesion a bit more rigorously. Of course, there may be circumstances where a weaker adhesion is desirable.

But for most book conservation applications — spine linings, board slotting flanges, hinges, sewn stuck-on endbands, covering material — strong adhesion is desirable.


The New Glue Pot from Lee Valley is Excellent. Gelatin and Paste for Lining Spines

Lee Valley Glue Pot

Lee Valley, perhaps the most innovative large woodworking tool company, recently introduced a one ounce cast stainless steel double boiler glue pot, which is perfectly sized for book conservators.

It works great with gelatin in conservation work or with hide glues for historic models. The heavy cast steel double boiler gives a very gentle and even heat.  It is based on a Landers, Frary & Clark glue pot from the 1870’s. There is an image of the original, which was cast iron, in Stephen Shepherd’s hide glue book. (1)

The cup-warmer is cheaply made, but it only costs a dollar when purchased with the gluepot. If the interior of the pot was finished a little smoother to make cleaning easier, it would be perfect. A steal at $35.00.

Arthur Green described his investigations using gelatin on the spines of books in the blog post, “Revisiting Animal Glue: Gluing-up with Gelatin” Traditionally bound books used animal glue on the spines, and paste for the covering and paste-downs: there must have been a reason. He tested starch paste and gelatin separately, and primarily for adhesion.

I find the real magic happens when gelatin and paste are used in sequential layers, or mixed together. Dudin, in the 18th century, described the “marriage” that happens between animal glue and paste. (2) A mix gives the book better resistance to torquing than paste alone, makes it feel more solid, and gives a more secure — yet still easily reversible — bond with a Japanese tissue for the first spine lining in conservation work.


  1. Stephen A. Shepherd. Hide Glue: Historical and Practical Applications (Salt Lake CIty: Full Chisel, 2009)
  2. R.M. Dudin. The Art of the Bookbinder and Gilder, Trans. by Richard Macintyre Atkinson (Leeds: The Elmete Press, 1977)

The Origins of Marbling: Glass?

Most of us think of marbling as paint or ink applied to a sized bath, usually manipulated somehow, then transferred onto a sheet of paper. This is essentially the definition put forward by Richard J. Wolfe, in his magnum opus, Marbled Paper: Its History, Techniques, and Patterns. His book is an invaluable resource, tracing the history of European marbling. The extensive plates dating particular patterns alone justify the price.

But what if we think of marbling not primarily as the transfer of colors, but the technique of using a stylus — or a number of them in a row, i.e. a rake — to manipulate strips or blobs of color into patterns? Visually, this is where most of the beauty and magic happens. And Egyptians were doing this as early as the 6th century BCE in glass.

Egyptian Alabastron and Flasks, 6th – 3rd century BCE. Corning Museum of Glass.

Recently I visited the Corning Museum of Glass,  which has some very early glass containers that look marbled. The museum catalog describes the center container as having the, “entire surface decorated with alternating registers of fine trails [thin threads of colored glass] wound ten to twelve times before changing color; all threads have been marvered in and dragged alternately up and down sixteen times to form an elaborate and delicate festooned or feathered pattern….” ( 55.1.61)

Instead of colors applied to a viscous bath, glass trails are wound around a container. Then they are manipulated with a point or stylus. The alternating up and down stylus movement at regular intervals is quite similar to how many styles of marbling are done even today.

Does specialization in the decorative arts cause us to overlook a fundamental cross-disciplinary technique like this one? Or, is this a common decorative technique that it is continually independently rediscovered. If so, are there other examples?