Presentation from ARSCOR (Archives and Special Collections Roundtable) meeting

1. Understanding
and Caring for
Architectural
Drawings and
Reproductions
Valinda S. Carroll
Preservation Manager
William R. and Norma B. Harvey Library
Hampton University
ARSCOR
January 24, 2013

2. Preservation Factors
• Substrate
• Media
• Process
• Environment/ Storage

3. Handmade Papers
• Rag writing papers in use through early 19th c
for all drawing types
• Handmade and mouldmade (cylinder) rag
• Hot pressed and gelatin sized wove paper
surface for ink washes and watercolors
• Rag fine art papers in use for competition and
presentation drawings through 1940’s

4. Machine Made Papers
• 1840’s low-quality paper sold on rolls
• Rough cartridge paper (originally handmade
cartridge paper in 18th c) available by 1840
• Detail and Manila papers lower quality for full-
scale working drawings, often colored paper;
not compatible with washes or watercolor

5. Translucent supports
• Prepared tracing paper: paper impregnated by
oil or resin (vegetable parchment or vellum)
• Natural tracing paper: heavily beaten pulp
• Parchment paper: fibers broken down by acid
• Tracing cloth or “linen:” coated cotton (1850-
1970)
• Cellulose acetate and polyester films (1940’s-
present) “Mylar”

6. Grids and Rules
• Pre-printed ruled grid lines; “cross section
papers” or “profile” papers first used by
Thomas Jefferson, borrowed from French
tapestry pattern makers
• Not common prior to 19th c
• Used by engineers

7. • Graphite pencil (18th c to
Media present)
• Colored pencils, crayons,
pastels (early 20th c)
• Iron gall ink: dark brown,
corrosive; used for
notations on drawings
executed with other media
(18th c to 1940’s)
• Japan ink: oxidized iron gall
ink suspended in vegetable
gum (mid 19th c)

8. More Media
• India ink: water-soluble ink based on
lampblack and animal hide glue (ink stick, not
bottled)
• Bottled ink: mid 19th c, various formulas
• Modern “India ink:” “waterproof” bottled ink
containing lampblack suspended in shellac-
alcohol solution
• Colored inks: sticks or bottled, pigment or dye

9. Diazo print
tan recto,
white verso
Positive
blueprint
Practice
identifying uniform paper
processes tone, Prussian
Blue image
color

10. Diazo print
• Soft lines
• Usually purplish-blue line on off-
white background (black, brown,
other line colors possible)
• May have “dirty” or hazy
appearance
• Verso lighter than recto (residual
phenols discolor paper)

11. Blueprint
• Usually negative image, embedded
in paper fibers (white lines on blue
ground)
• Blue recto with white verso
• Ferric ferrocyanide “Prussian blue”
color (not violet/purple)
• Copied from translucent original
• Pellet print slightly different from
blueprint positive (image on surface)

12. evidence of damage to
tracing paper support
of original (master)

13. Hectograph
•alcohol-based
•fugitive color
•1880-1920 for
architectural use

14. Aniline Print
• 1860’s -1870’s most popular
• Used by engineers and contractors rather than
architects
• Blue, black, or purple line with soft edge
• Greenish tint (“green print”) background
• Coating only on recto
• Image fades easily

15. Silver Halide processes
• Photostat (1909): silver • Silver gelatin contact
halide usually negative print (1890’s-1940’s):
• CB “Dupro” “wash-off” opaque or translucent,
print on tracing cloth high-contrast or
(1920’s): silver halide continuous tone image
black line print • Autopositive, Kodak Q,
Retroflex print (1947) :
silver halide black line
on acetate or Mylar

16. Photostat
• Cool black and white image with emulsion
• Often negative, but positive image post-1953
• Could reproduce a non-transparent original
• Silver mirroring
• Brown staining or liquid tide lines on verso
from inadequate fixing or inadequate rinsing
• Small, standard dimensions

17. Photomechanical processes
• Direct carbon and • True to scale print/
powdered carbon lithoprint/ gel litho
(1880’s-1910’s): black (1904-1950’s)
pigment in gelatin, line • Electrostatic print
or half-tone positive (1948); large format
• Photolithography 1970’s, vellum, paper ,
(1870’s) or Mylar

18. Chemical Hazards
• All silver halide • Prints from different
processes are sensitive processes should be
to sulfur isolated by Melinex
• Most processes are folders, Microchamber
alkali sensitive Silversafe paper, etc.
• Diazo and sepia prints • Folders and interleaves
offgas and damage should pass P.A.T.
adjacent documents • Use pH neutral interleaf

19. Storage
• Flat files are best option • Up to ten items in one
• Powder-coated steel, folder (interleaved)
not baked enamel (to • Place interleaving paper
avoid off-gassing VOC) inside encapsulation or
• All items stored flat in Melinex folder to
folders absorb degradation
• Individual folders best products
option

20. Rolled Storage
• Rolled storage for • Roll with interleaf or
flexible oversized Melinex folder (seam or
material fold parallel to tube)
• Roll onto 4” diameter or • Provide support for rolls
larger tube • Store unsupported rolls
• Isolate acidic tube with in shallow boxes to
Marvelseal (best) or prevent distortions or
Melinex (short-term) tears (short-term)

21. Resources
• Price, Lois Olcott. Line, shade, and shadow : the fabrication and
preservation of architectural drawings. New Castle, DE : Oak Knoll
Press, 2010.
• Price, Lois Olcott. “History and identification of photo-reproductive
processes used for architectural drawings prior to 1930.” Topics in
Photographic Preservation. Washington: American Institute for
Conservation, 1995: 41-49
• Kissel, Eléonore and Erin Vigneau. Architectural photoreproductions
: a manual for identification and care. New Castle, DE : Oak Knoll
Press, 1999.
• Kissel, Eléonore and Erin Vigneau. Architectural photoreproductions
: a manual for identification and care[ 2nd ed.]. New Castle, DE : Oak
Knoll Press, 2009.