1. Mammoth Materials
How to Preserve Posters,
Maps & Drawings
LYRASIS Preservation Services
Funded in part by a grant from the National
National Endowment for the Humanities,
Humanities, Division of Preservation and
and Access
Unit 2

2. Unit 2:
• Architectural and map reproductions
• Guide to identification
• Silver processes

3. Architectural and Map
Reproductions…
Some Vocabulary
• Ground: refers to the
area of the print that does
not contain any lines—
think background.
• Negative Print: for
architectural materials,
negative prints are prints
with light lines on a dark
ground.
• Positive Print: are prints
with dark lines on a white
ground.
Is this a negative or positive print?

4. Vocabulary Question
• Is the illustration on the previous slide a
positive or a negative print?
Answer:
It is a Negative Print – a print with a dark
ground and light lines.

5. Architectural & Map
Photoreproductions
Photo courtesy of the Georgia Archives
The following slides are a
partial list of commonly
used techniques for large
format copying and dates
of use.

6. Architectural & Map
Photoreproductions
•Blueprint (1842 – present)
−Blueprint by far the most common and widely
recognized paper or cloth; surface has raised fibers
•Pellet Print (1842 – 1920s)
−Pellet print or blue lines is the same process BUT two
other types on this list produced blue writing on white
background

7. Architectural & Map
Photoreproductions
• Vandyke Print (1889 – 1930s)
– Vandyke process is very similar to blueprint –
metallic salts solutions were exposed to light
and produced a brown tone rather than blue –
more than often these are a negative image, a
white writing on a colored background.

8. Architectural & Map
Photoreproductions
•Ferrogallic Print (1861 – 1930s)
− Positive prints. Blue-black lines with metallic
sheen when created – often faded browns blacks
on brittle paper – creating low contrast images.
Used most often in Europe in the 1800 – never
took off like the blueprint.

9. Architectural & Map
Photoreproductions
• Anailine Print (1864 – 1890s)
– Used a synthetic dye on paper or cloth.
Purple, blue or black. Always positive prints.
Ground may be flecked but uniform in color
(unlike diazo). Usually on degraded support,
with a high quality substrate and low contrast.

10. Architectural & Map
Photoreproductions
• Hectograph (1870 – 1900s)
– Not a photoreproduction – hand
lettered/drawn, positive, purple-blue color.
Similar look to diazo.

11. Architectural & Map
Photoreproductions
The next slides are further listings of
processes used for large format copying.
This is not comprehensive, but it will help
to illustrate the variety of possibilities
within oversized collections.

12. Architectural & Map
Photoreproductions
•Diazotype (1880 – present)
− Diazo processes – positive prints with
mottled ground, multiple colors possible,
blues mimic pellet prints. Support paper,
plastic or cloth. Still in use. Smooth surfaces.

13. Architectural & Map
Photoreproductions
• Sepia Diazo Print (1920 – present)
– Sepia are usually warm brown lines and
primarily on transparent substrates, such as
plastic film or translucent papers – sometimes
impregnated with oils or chemicals – may still
have a strong odor. Still in use.

14. Architectural & Map
Photoreproductions
• Gel-Lithograph (1900 – 1930s)
− Trade names- True-to-scale, Ordoveraz,
Velograph, Fotol print, Fulgur print, and Guild.
Dark line positives. But any color – use printing
inks. Paper or cloth. Lines are actually raised
and sitting on top of the surface. This can be
seen using a magnifying glass.

15. Architectural & Map
Photoreproductions
• Electrostatic Print (1948 – Present)
– Electrostatic large print photocopy, stable
toner, still in use.

16. Architectural & Map
Photoreproductions
• Photostat (1909/1953 – 1970s)
– negatives (earlier) or positives (later version in
1953). Usually smaller in size 18 x 24, but
larger also produced. Opaque paper only.
Distinguished by silver mirroring of dark
areas. Brown fixer stains sometimes on
reverse.

17. Architectural & Map
Photoreproductions
• Wash-off Print (1920 – 1960s)
− positives with dark, black ink-like lines. All
supports. Image in reverse (on back) and read
using transmitted light. Called wash off because
of the ability to erase the line and correct
drawings right on the support. It was the earliest
silver process to duplicate architectural plans.

18. Guide to Reproductions
• The following slides are general guides to
assist in identifying printing techniques.
• They are not comprehensive.

19. Guide to Reproductions
by Color of Background
• Blue
− Blueprints
• Brown
− Negative Vandyke Print
• Black or Gray
− Negative Photostat or Electrostatic Print
• Greenish White
− Aniline Prints

20. Guide to Reproductions
by Color of Writing
Blues
• Blue Lines (Positive Blueprint) or Pellet Prints
• Diazotypes
• Hectographs
• Aniline Prints
Browns
• Kallitypes or Van Dykes
• Sepia Diazotypes
• Ferrogallic

21. Guide to Reproductions
by Color of Writing
Black or Grays
• Electrostatic (e.g. Xerox)
• Photostat
• Wash-off Print
• Aniline Prints

22. What am I?
It’s hard to tell from a picture, but what do you think?
What types of processes are in this folder?

23. What am I?
•Diazo on top (dated 1969); smooth surface
•Blueprint on bottom (no date), raised surface
A good rule of thumb when you are unsure of the type of
oversized material you have—segregate them by material
type so that it won’t harm anything it comes in contact with
and limit its exposure to light.

24. Silver Processes
• Some of the early copying processes were
variations of photographic processes and involve
various silver compounds much like photo
processes. Like photographs, these have special
handling and storage issues.
• Vandyke prints
• Fixed Line Silver Halide Prints
• Photostats

25. Silver Processes
• Vandyke prints- found as both negatives
and positives. When they are negatives,
they appear as white lines on a brown
background, and as a positive, they are
brown lines on a white ground. Image
formed of silver and iron. High contrast
images. While the brown color can vary, it
is warm – bronze brown. The positive
Vandykes look very different from a Sepia
Diazo in spite of the fact that both have
brown lines on a white ground– Sepia
Diazos have low contrast, dirty ground,
and a red-brown hue.

26. Silver Processes
• Fixed Line Silver Halide prints are
positive reproductions—black lines
on white ground. Paper or plastic
substrate. Not very common.
• Photostats copier exposed image
onto sensitized paper. Small window
of use 1950s – 70s. Large sizes
were available, but not as widely
used like blueprints.
Photostat, United States. Coast and Geodetic Survey. 1928
Courtesy of Richter Library, University of Miami, Coral Gables, Florida

27. Silver Processes
• Silver processes should be
segregated from Diazo materials.
Diazo reproductions contain
residual sulphur products that
damage other materials, and are
especially damaging to silver-base
processes. These should not be
stored together without using poly
sleeves or some other means of
isolation.

28. Silver Processes
• All Enclosures Should Pass
Photographic Activity Test (PAT)
− ANSI Standard IT9.16-1993, developed to test
reactions of photographs to chemicals and
additives commonly found in paper enclosures:
− Tests were done for staining of gelatin and fading
of silver.
• Limitations
− Test for paper enclosures only does not include
plastics.
− Applies only to photographs that are silver
images.

29. Plastic Substrates
• Another clue can be found in the
substrates—the following processes can
have plastic substrates
− Wash-off prints
− Photo processes
− Blue and Sepia Diazo
− Electrostatic

30. Architectural and Map
Photoreproductions
• Blueprint
• Pellet Print
• Vandyke Print
• Ferrogallic Print
• Anailine Print
• Hectograph
• Diazotype
• Sepia Diazo Print
• Gel-Lithograph
• Electrostatic Print
• Photostat
• Wash-off Print
Still not sure…???

31. Architectural Photoreproductions:
A Manual for Identification and Care
A great book that will answer just about
all of your identification preservation
questions. In this book, you will find:
• Comprehensive identification
information
• Details on preservation issues by
format
• Recommended enclosures
• Methods for reformatting damaged or
unstable formats.
by Eleanore Kissel and
Erin Vigneau

32. Section 2 Quiz
What did you learn?

33. Section 2 Quiz
Question 1:
• It is important to separate oversized
materials by printing process.
True or False ?

34. Section 2 Quiz
Question 1:
• It is important to separate oversized
materials by printing process.
True or False ?
Answer : True
Some printing processes may involve
chemicals that could be harmful to other
print types.

35. Section 2 Quiz
Question 2:
• It is easy to identify the printing method
that has been used.
True or False ?

36. Section 2 Quiz
Question 2:
• It is easy to identify the printing method
that has been used.
True or False ?
Answer : False
Even though each printing process has
some unique characteristics, they often
share traits with other processes. There
are resources available to help with print
identification.

37. Thank You!
To continue Mammoth Materials,
View Unit 3
Contact us if you have any questions.
LYRASIS Preservation Services
preservation@lyrasis.org