Canvas reweave treatment on a large mid century oil painting.
Canvas torn by puncture caused by impact. Impact resulted in 3 tears and splintered crossbar joint. Canvas stored in damaged state for a number of years, causing severe deformation of canvas.
Canvas loosened from stretcher on 2 of the 4 tacking edges. Crossbars removed. Canvas reattached to stretcher edges, leaving the canvas with a loose tension. Canvas propped in a stable but comfortable position to examine both the front and the back. Good lighting, tools, and OptiVisor positioned within reach.
Move canvas to wall with the reverse outward. Slip a piece of foamboard with silicone mylar attached between the wall and the painting surface. Secure canvas so that it does not fall forward but is flush with the foamboard and steady against wall.
1. Examine the tear closely: chart the threads, note the contortion, establish those threads that will carry the torque, and identify those threads most useful to bridge the gap. In this case, the weft threads were the primary carriers of strength.
2. The thread pattern was charted with tiny pencil dots on corresponding threads on each side of the gap. Sutures (6/0 Polypropylene) were laced into the canvas thread at the dot, laced again to the corresponding dot and knotted. This directed the distorted weave in proper alignment. Work in manageable segments. Groom the severed threads with moisture and sturgeon glue/wheat starch paste.
3. Weaving proceeds, taking advantage of the longer threads to pull the gap together. Straight pins are useful to temporarily situate threads strategically prior to adhesive. The pins can stick into the foamboard behind the canvas.
4. A heated tacking iron seals the sturgeon glue paste with the threads. The weave stays in place but can be unwoven for any do-overs.
5. Proceed along, removing the sutures if they get in the way or adjusting tension and alignment with new sutures.
6. Conscience of the waffling around the repair, try to minimize by pulling or pushing to better alignment. Sometimes a light water spritz on surrounding canvas can ease some tension.
7. Though working progressively is generally good, there may be segments that should be aligned and adhered prior to other areas. In this long tear, it helped to deal with the mid section to balance the torque.
8. The longest and strongest weft threads are reserved for final placement. These were strong enough to be pulled tight.
9. Completed weave, reverse.
10. Completed weave, obverse.
11. A Hollytex patch adhered with Beva film provides some additional support.
Detail of a poster presented at the Symposium. It was part of a thesis from Academy of Fine Arts in Kracow, Poland.
I was fortunate to attend one of the Getty grant initiatives, Conserving Canvas. It was held at Yale University Oct 15-17, 2019. Conserving Canvas Symposium, along with 19 other initiatives, are made possible by a generous grant from the Getty Foundation. The aim of the grant is to focus into the study of canvases in the field of art conservation.
At the Yale Symposium, issues that pertain to the preservation of the support of a painted work of art were presented and discussed. Theory, methods, and materials were shared by some of our most accomplished professionals in the field, worldwide. Valuable information ranging from old world glue lining recipes to innovative nanocellulose adhesives was presented in a spacious university auditorium before a packed audience.
I returned with a binder full of useful information, network connections, and practical tools. But the biggest ‘take-away’ was the spectrum of worldwide approaches to a very specific issue. All of the nationalities have different and distinct traditions, resources, and conceptual priorities. Should a failing canvas by lined? Should a frail canvas be loaned out? Has common practice done more harm than good? What if you don’t have 21st Century resources?
Within this Symposium, there were no right nor wrong treatments; there was only something new to learn.
Thank you, Getty Foundation, for opening the world a little more.
Turned Out to be a Pretty Nice Day, After All
This little panel painting on board is dirty, or was dirty.
Besides completely masking the design, the colors, and the details of this picture, the surface dirt has swapped the crisp March morning for a dour November afternoon.
The dirt is not just a layer that has settled on the paint surface. It is a complex interaction of carbon, hydrogen, oxygen, nitrogen, silicon, phosphorus, proteins, salts and minerals in an ionic dance with the pigments and the resins of the painting. These elements have been trading ions for years. So any agent used to clean the dirt away, necessarily changes the chemistry of the original material. That is why a Professional Conservator will choose a cleaning agent that can capture the dirt without pulling away essential compounds of the original pigments and binders. With the return of the original design, colors, and details, comes the fresh frosty air of a March morning.
Clear Your Brow
Art Conservators are relaxing with fresher air these days. Thanks to Conservation scientists, like Chris Stavroudis and others, cleaning paint surfaces are moving away from heavy solvents to more user and environmentally friendly solutions. Chris conducted a Workshop on his Modular Cleaning Program at the St. Louis Art Museum this past month. Under an IMLS grant petitioned by the Missouri Botanical Garden and attended by many Missouri conservators, the Workshop offered a new, cleaner age of conservation.
Watt Restoration March 2017
Cleaning Soot From Painting Surface and Collateral Damage
Fireplace soot is a common yet insidious grime on the surface of an oil painting. If the painting has had a layer of varnish, removal of soot is easier. But if the varnish has aged and cracked, exposing the paint layers to the settling soot, removal is tricky.
In the example, a early 19th Century still life by Ella Sophonisba Hergesheimer, the soot is most clearly imbedded in the frame rabbet margins and the center paint damage. An aqueous solution with strong surfactant did not remove the soot satisfactorily. Besides, the layer of discolored varnish had to be removed as well. An acetone/xylene Carbopol gel worked effectively on the aged varnish, as well as the soot.
The gel was cleared with an aqueous/surfactant solution that removed residual varnish and soot. The tricky issue was that affecting the top layer of paint was unavoidable. Largely this was due to the chemical change of the surface paint layers in the years of exposure to the soot and to the air. It goes against a conservator’s conscience to jeopardize original paint, but in an effort to extend the life and aesthetic of the work, a compromise was reached.
The more vulnerable pigments, like the umbers and the lakes were cleared of the varnish and soot with the strong and quick acetone gel. As the debris indicates in the image to the right, the black soot came off, the amber/green varnish came off AND some of the top layer of damaged umber paint. The clearing left behind a canvas/ground/paint composite that could be safely consolidated and flattened. The color revived yet the overall tone and painterly details remained.
Watt Restoration March, 12. 2016