Charles Zug Painting 

Dickinson College


Varnish Deterioration on Charles Zug PortraitDickinson College contacted B.R. Howard & Associates to provide a condition assessment and perform conservation treatment of their Charles Zug portrait. The painting was carefully packed and transported to our studios for a thorough examination.


It was found to have extensive traction cracking, along with some lifting or tenting of the paint. An old deteriorating varnish layer covered the surface of the painting, which visually disfigured its appearance.


The lower stretcher bar had created a crease in the paint film close to the bottom, and several of the stretcher keys were missing, causing the painting to become loose.



Half Cleaned PortraitThe painting was extensively photo documented, and then surfaced cleaned using a mild enzymatic cleaning solution. The deteriorating yellow varnish was removed using an acetone/ethanol cleaning gel. It was then rinsed using de-ionized water applied with cotton cleaning swabs.


The flaking/cracking paint was locally injected with a consolidant, and set down using a heated tacking iron over a layer of silicone release Mylar sheeting.


The missing stretcher keys were replaced, and the painting was lightly stretched by increasing tension on the original stretcher bars. The surface was given a clear, non-yellowing isolation varnish to protect and saturate the original surface.


The painting was placed back in the frame, and an acid-free dust cover was attached to the back. The Charles Zug Portrait was then returned to the college.


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