Restoring the Tiffany Glass

The Tiffany glass was restored by Botti Studio in Evanston. The Botti family has worked with glass since the 1600s. Many of the restoration techniques still used are centuries old.

Before a panel can be worked on, it must be “mapped.” A tiny label with an identification number was placed on each piece of glass within the panel. Three sets of charcoal rubbings were made for each panel; the rubbing became the record of a panel and the blueprint for its accurate recreation. One set of rubbings was added to the project’s permanent archives, so that future curators of the dome will have records showing what was done in 2008. Information such as the number of each piece of glass, comments about it and measurements of the thickness of the leading were recorded on the rubbings. Photos with and without background light shining through the glass were taken.

Starting at a corner, the lead came was unwound from around each piece of glass, one at a time. The piece was dipped into a solution of conservator’s soap, the same soap used to clean horses’ manes and tails, then cleaned with a soft wire brush and a razor blade to remove decades of encrusted putty and dirt.

Cracked pieces were carefully glued. Missing or mismatched pieces (from previous repairs) were replaced with new glass created specifically to match. To show what was needed, Botti sent pieces of the Tiffany dome glass to several glass companies that have been in business for decades, including some that provided glass for Tiffany. Getting the right match was an exacting process that requires the glass company to create several rounds of samples before achieving the right colors and textures to blend into a specific position in a panel.

When all the pieces of glass in a panel were readied, the next step was to wrap the new lead came around each piece. To assemble the pieces back into a panel, the glazier constantly referred to the rubbing to lay out the pieces correctly. Working on a thick wooden board, the bottom row of pieces was set into the channel of the came. Each row of pieces was placed next to the previous row. To hold them into place, flat-sided horseshoe nails were driven behind each row, until the panel can be bound with channel around all sides. The pieces were soldered together, making the panel whole again. Short pieces of copper wire were soldered onto the leading; they fit around a system of support bars, called “saddle bars.” The smaller panels near the top of the dome are flat; those lower down are concave.

The panels were reinstalled in Preston Bradley Hall over four days at the end of June 2008, and the room reopened on July 1.