Uploaded February 2022 | Updated September 2026, 3 days ago
Blueprints are a delicate, but important material in the museum’s collection. Sarah Casto, assistant conservator at the George Eastman Museum, shares how we conserved the original blueprints from George Eastman’s gardens, originally created in 1903, so that we can preserve these documents and continue to use them in our research.
When the bluepionts came to the conservation lab, they had many tears that likely occurred from handling and use as an architectural document. Most of the tears were repaired on the back with pressure-sensitive tape sometime in the past. The tape was beginning to discolor with age, and new tears were forming along the edges of the tape, a sign that the tape should be removed.
Heat was the best method to remove this particular tape. This tool is a hot air pencil - it blows a gentle, controlled stream of warm air at the tape. The heat softened the adhesive and allowed our conservators to remove the plastic tape carrier with a spatula. Then they removed any remaining adhesive using an adhesive pick-up eraser. The adhesive appeared dark because it also contains dirt from the back of the blueprint.
Next, they surface cleaned the back of the blueprint. To do this, our conservators grated white vinyl eraser into small crumbs and gently rolled these crumbs over the surface of the blueprint. This technique increases the surface area of the eraser to remove dirt more quickly without causing abrasion to the paper.
They used a block eraser to carefully clean the edges of the tears, where the small eraser crumbs could become trapped or cause more damage. Surface cleaning is important so that dirt does not become embedded in the new repairs. They carefully brushed away all of the eraser crumbs using a soft brush.
Once clean, the tears were repaired from the back using wheat starch paste and Japanese paper. Paste has excellent aging properties and the paper is both thin and strong, providing a much more stable mend than tape. The paste was applied to strips of Japanese paper, which were positioned over the tears and lightly burnished into place. Our conservator used polyester fabric to keep their tools from sticking to the wet paste and paper. The mended areas were dried under blotting paper and weight to prevent the new mends from causing any distortions as they dried.
Some areas of the blueprint were completely detached when the tape was removed, and needed to be reassembled like a small puzzle. In all, there were over 60 inches of tears to repair. After the repairs were dry, the blueprint was turned face-up so they could examine the mended tears from the front.
The last step, although not necessary, was to “inpaint” some of the repaired tears. Inpainting makes the tears less visible, which helps viewers read the lines and text more easily. Using a very fine brush, the conservators applied a layer of gelatin to the tears, followed by watercolors. The gelatin prevents the watercolors from sinking deeply into the paper fibers, and the watercolors help minimize the visibility of the white paper support along the torn edges.
The blueprint was photographed before and after treatment, and this video compresses approximately 35 hours of treatment into 3.5 minutes.
Blueprints are a delicate, but important material in the museum’s collection. Sarah Casto, assistant conservator at the George Eastman Museum, shares how we conserved the original blueprints from George Eastman’s gardens, originally created in 1903, so that we can preserve these documents and continue to use them in our research.
When the bluepionts came to the conservation lab, they had many tears that likely occurred from handling and use as an architectural document. Most of the tears were repaired on the back with pressure-sensitive tape sometime in the past. The tape was beginning to discolor with age, and new tears were forming along the edges of the tape, a sign that the tape should be removed.
Heat was the best method to remove this particular tape. This tool is a hot air pencil - it blows a gentle, controlled stream of warm air at the tape. The heat softened the adhesive and allowed our conservators to remove the plastic tape carrier with a spatula. Then they removed any remaining adhesive using an adhesive pick-up eraser. The adhesive appeared dark because it also contains dirt from the back of the blueprint.
Next, they surface cleaned the back of the blueprint. To do this, our conservators grated white vinyl eraser into small crumbs and gently rolled these crumbs over the surface of the blueprint. This technique increases the surface area of the eraser to remove dirt more quickly without causing abrasion to the paper.
They used a block eraser to carefully clean the edges of the tears, where the small eraser crumbs could become trapped or cause more damage. Surface cleaning is important so that dirt does not become embedded in the new repairs. They carefully brushed away all of the eraser crumbs using a soft brush.
Once clean, the tears were repaired from the back using wheat starch paste and Japanese paper. Paste has excellent aging properties and the paper is both thin and strong, providing a much more stable mend than tape. The paste was applied to strips of Japanese paper, which were positioned over the tears and lightly burnished into place. Our conservator used polyester fabric to keep their tools from sticking to the wet paste and paper. The mended areas were dried under blotting paper and weight to prevent the new mends from causing any distortions as they dried.
Some areas of the blueprint were completely detached when the tape was removed, and needed to be reassembled like a small puzzle. In all, there were over 60 inches of tears to repair. After the repairs were dry, the blueprint was turned face-up so they could examine the mended tears from the front.
The last step, although not necessary, was to “inpaint” some of the repaired tears. Inpainting makes the tears less visible, which helps viewers read the lines and text more easily. Using a very fine brush, the conservators applied a layer of gelatin to the tears, followed by watercolors. The gelatin prevents the watercolors from sinking deeply into the paper fibers, and the watercolors help minimize the visibility of the white paper support along the torn edges.
The blueprint was photographed before and after treatment, and this video compresses approximately 35 hours of treatment into 3.5 minutes.
