III
In addition to the dimensions and the markings, there are many other
characteristics of paper which the bibliographer could conceivably take into
account. The paper industry has developed a wide range of procedures and
machines for testing various properties of paper in order to maintain
standards and to identify precisely the features of any given sample.
Although these tests are usually applied to modern machine-made paper,
they could be employed to ascertain the characteristics of earlier papers as
well. Some of them are not
appropriate for bibliographical work, but the bibliographer should be aware
of the general range of physical, chemical, and optical characteristics which
are mechanically testable. The physical characteristics can be subdivided
into five categories: (1) substance, involving such matters as basis weight,
thickness, bulk, and bulking thickness; (2) strength, as revealed by tests for
tensile strength (e.g., Schopper static tester, Van der Korput dynamic
tester), bursting tests (Mullen, Schopper-Dalen), tearing tests (Elmendorf),
and folding tests (Schopper); (3) permeability and absorbency (as tested by
the Gurley densometer, the Potts permeability apparatus, the Cobb method,
the Currier apparatus, and so on); (4) formation (as indicated by the degree
of uniformity of transmitted light); and (5) smoothness (judged by
microscopic or photographic techniques or by the flow of air between the
paper and a standard surface). The chemical characteristics can be
determined by tests for (1)
the fiber and mineral constituents of a furnish; (2) the sizing agents (gelatin,
rosin, casein); and (3) acidity and alkalinity (both colorimetric and
electrometric tests). Finally, the optical properties fall into three groups: (1)
color (tested against a standard or by spectrophotometer) and whiteness
(tested by the Zeiss Leukometer); (2) gloss (surface reflectance measured
by such instruments as the Ingersol Glarimeter or the Sheen Gloss meter)
and brightness (General Electric Brightness meter or Institute for Paper
Chemistry Automatic Color and Brightness Tester); and (3) opacity
(measured by a photometer).
[64]
Some of these tests can be ruled out immediately for bibliographical
purposes because they entail destruction or mutilation of the
paper (all the tests for strength fall into this category). Others, though they
do not damage the paper, are impractical for a bibliographer to undertake
because they involve precision instruments which are not easily portable and
are not available in libraries (many of the optical tests fall into this
category). In any case, the details established by most of these tests are not
of primary relevance to bibliographical studies. Since a verbal description
of a physical object necessarily represents a selection of details out of an
infinite number of possible details, an intelligent description depends on a
systematic selection of details made in the light of the purposes for which
the description is intended. The elaborate tests performed in the paper
industry do not provide exhaustive coverage of every conceivable property
of paper, but they furnish those details necessary for the efficient operation
of the industry. Similarly, the description of paper in a bibliography should
record only those characteristics which are of primary interest to the
persons for whom the bibliography is prepared—in general, students
of
literature, of history, and of printing and publishing. One cannot, of course,
say that such details as the tensile strength or the chemical composition or
the opacity of paper are necessarily irrelevant to historical study; the student
of book production in a particular period would doubtless be happy to have
a large body of such information available for his use in
author-bibliographies. But one can say that these kinds of detail are not of
primary importance to the majority of users of a bibliography and that the
practical difficulties they involve outweigh their usefulness for this
audience. If, in certain instances, some of these details do turn out to be of
significance in establishing the printing history of a book, they can then be
recorded — the classic case is Carter and Pollard's use of evidence
regarding the composition of
paper in detecting the Wise forgeries. Only the bibliographer who has a
detailed knowledge of a particular situation will be in a position to decide
whether or not some of these tests are likely to be fruitful for his purposes;
when he thinks they may be, he can turn for assistance to an appropriate
laboratory, but it would be absurd to require him to go to such lengths as
part of the ordinary routine of bibliographical description.
[65] In the light of these considerations,
only
two of the tests employed in the paper trade — those for thickness
and
color — seem appropriate for bibliographical use, while a third
group of
the tested characteristics — those relating to finish — can be
treated
bibliographically in a less precise fashion.
(1) Thickness. The measurement of paper thickness is
one
of several related measurements of primary importance in the paper
industry. Of these, the basic measurement is that of the "substance" of
paper, generally expressed in terms of "basis weight" — that is, the
weight per standard unit area (usually, per ream of specified
dimensions).[66] Thus the designation
"35 x 45, 100 lbs., 516's" describes a paper of which a 516-sheet ream,
with each sheet measuring 35 x 45 inches, weighs 100 pounds. A more
convenient method of indicating substance, based on the metric system, is
to specify grams per square meter; in this way only one figure need be
given, since it is not dependent on the size of the sheet. Instead of saying
"35 x 45, 100 lbs., 516's," one can simply say "87 g.s.m."[67] Although the substance of paper
is one of
its most prominent characteristics, measurement of substance cannot
normally be performed in
bibliographical work, since the bibliographer is not usually in a position to
weigh the sheets of a book separately from the binding, endpapers, and
inserted plates. If he cannot make this measurement, then he cannot present
other figures based on it, such as "bulk," the ratio of the thickness of a
sheet to its substance.[68] The thickness
of a sheet, on the other hand, is not obscured when the sheet is folded and
bound into a book; it is thus available for direct measurement by the
bibliographer, and it should be reported in his description of paper.
Measurement of the thickness of a single sheet of paper is performed
with a micrometer caliper. Many styles of micrometers are available (both
spring-actuated and dead-weight-actuated), and most of them can be used
for measuring paper thickness; since suitable pocket models can be
purchased for about $30, every bibliographer should have one as part of his
standard equipment.[69] They are
manufactured with dials graduated in fractions of inches or in fractions of
millimeters, and the bibliographer should choose one with a dial
corresponding to whichever system is being used for other
measurements.[70]
The sheets of a given book may vary in thickness, according to the
micrometer readings, and the significance of such variation may differ
according to the period and type of paper. In handmade paper, if the
chainlines and watermark suggest that all the sheets were intended to be
"the same paper," certain variations in thickness may be of no importance,
and one can report either an average reading or the range of readings; but
in machine-made paper a slight difference in thickness between two sheets
can indicate that two stocks of paper were used and may even be important
in distinguishing between two impressions.
[71] Therefore, one should normally
take a
micrometer reading on one leaf in every sheet (if not on every leaf, as a
test for cancels). When a representative reading for each paper is arrived
at, one simply records the reading in the description, along with the citation
of a specific leaf which yields that reading, in some such form as the
following: "thickness .003 in. (B3)," or "thickness .076 mm. (B3)," or
"thickness 76μ (B3)."
[72]
Some bibliographers in the past have reported the thickness of all the
sheets of a book taken together, in such a form as "sheets bulk 1 7/16 in."
This kind of measurement is useful in enabling a reader to visualize the
thickness of a book and serves as a guide to the "bulking thickness" of the
paper. When the figure for the total thickness of the leaves of a book is
divided by the number of leaves, the resulting figure is nearly always larger
than that representing the thickness of a single sheet as measured with a
micrometer; this larger figure is known as the "bulking thickness" and is
an important characteristic of paper. For these reasons the bibliographer
should continue to record the total bulk of the sheets (and perhaps the
calculated bulking thickness of a single sheet), even though a micrometer
reading of the paper thickness is given also. Such a measurement, however,
is often not very precise because it can vary with the amount of pressure
applied to the sheets
when the measurement is taken and with the
particular place on the edge of the book chosen for measurement. The
center of the top edge is usually the best place to measure if a ruler is used,
but calipers that reach in to the center of the leaves provide a more
dependable reading; whichever method is employed, only those leaves
comprising the sheets that went through the press are to be measured,
excluding any endpapers and binder's leaves.
[73]
Even with these precautions, the measurement is not dependable
enough to be relied upon in bibliographical analysis whenever much
precision is required. If, for example, some copies of a particular book are
printed on uniform paper throughout and other copies include one gathering
made up of heavier paper, the variation in total bulk between copies of each
kind may be so slight as to seem insignificant to the bibliographer; he may
dismiss the variation (especially if he does not have copies yielding the two
readings side by side) as due simply to the ways in which he held the copies
when taking the measurements. But if he had taken micrometer readings of
each sheet, he would have known that the variation resulted from the
presence of a heavier sheet in some copies. Of course, chainlines and
watermarks also serve to distinguish between papers in some books; but,
for books printed on wove unwatermarked paper, micrometer measurement
may be the only easy way of detecting mixed
papers — and thus of locating what may be called "sheet-cancels"
(substituted sheets rather than single leaves), not uncommon in
machine-produced books.[74]
Whenever a book does contain mixed papers, the figure for bulking
thickness (as opposed to total bulk), if it is to have meaning, must be given
separately for each different paper and must be based on the bulk of
particular sections of the book; in such cases, dividing the total bulk of the
entire book by the number of leaves gives only an average and tells one
nothing about the bulking thickness of the individual papers involved. For
this reason, figures for bulking thickness — when they are deemed
significant enough to report — should be associated not with the
figure
for total bulk but with the other characteristics of the individual papers. A
convenient way to put the figures for bulking thickness in proper
perspective is to place them
immediately after the figures for the thickness of single sheets (with a
parenthetical indication of the section of the book which served as the basis
for the calculation): "thickness .076 mm. (B3), bulking .079 mm. (B-G)."
The one figure for total bulk of the sheets should come later in the
description, since it is a feature of the finished book, not a characteristic of
any of the papers involved.
(2) Color. The most precise way of specifying color,
in
paper as in other objects, is in terms of spectrophotometric measurement;
but a simpler — yet reliable and scientific — method, also
used when
appropriate in the paper industry, is visual comparison against a standard.
Since the Centroid Color Chart worked out by the Inter-Society Color
Council and the National Bureau of Standards has been recommended for
other instances of color specification in bibliographical description,[75] it is an appropriate choice for the
reporting of color in paper also. Certainly the same system of referring to
color should be used throughout a bibliography, and the ISCC-NBS
dictionary offers a convenient way of converting all specifications to the
ISCC-NBS system regardless of the color chart originally employed.
Furthermore, Deane B. Judd, writing in the Paper Trade
Journal, has specifically shown the applicability of the ISCC-NBS
names to the
description of paper.[76] The
advantages of the system, in terms of general acceptance and convenience,
outweigh its two chief disadvantages: the glossiness of the centroid color
chips and the limited distinctions the centroid chart makes among the
common colors of printing papers. The two are related, for the less fine the
discrimination required in specifying color, the less important the distortion
created by surface texture. Of the 267 ISCC-NBS color-name blocks, only
seven are of much use in describing the papers generally employed for
printing books: white (Centroid 263), pinkish white (9), yellowish white
(92), greenish white (153), bluish white (189), purplish white (231), and
light gray (264). The colors of the majority of book papers, in fact, fall
nearer the centroid chip for "white" than any of the other chips. Several
methods of measuring and specifying more accurately the various degrees
of whiteness in paper have been developed in the
paper industry,[77] but under most
circumstances the bibliographical significance of the precise color of paper
is not great enough to warrant
the use of spectrophotometers and other elaborate equipment. In unusual
instances the bibliographer may find it necessary to turn to these methods;
but he need not make them part of his standard routine, for the information
they yield would often prove more distracting than helpful to the readers of
descriptive bibliographies. Ordinarily, therefore, the distinctions among
near-whites provided by the ISCC-NBS centroid chips, though not subtle,
are adequate for bibliographical purposes. Indeed, since the nearest match
will usually be "white," a bibliographer may wish to establish the
convention within an individual bibliography that all papers described are
white unless otherwise specified; on the other hand, it does no harm to
repeat "white" in each instance, since the word takes little space and
emphasizes the fact that the color of the paper has been taken into account.
It is perhaps unnecessary to cite the centroid number for white, but for
other colors a parenthetical reference
to a visual standard should always be provided. If a bibliographer describes
a paper as "yellowish white (Centroid 92)," the reader knows that the color
of the paper, though not necessarily an exact match, falls within that
color-name block of which centroid chip 92 is representative.
(3) Finish. The finish of paper is one of its most
prominent characteristics, involving such related properties as gloss,
brightness, and smoothness. Since the general roughness or glossiness of a
piece of paper immediately catches the eye, it is reasonable to expect that
a description of paper should take this quality into account. The only
accurate way of measuring gloss, however, is in terms of the surface
reflectance of light, and the test for smoothness is in terms of the surface
flow of air; these procedures again involve instruments which make finer
discriminations than are generally usable or meaningful in a bibliography.
What will usually suffice, for bibliographical purposes, is a simple verbal
description of gloss and smoothness, preferably in the form of a single
adjective (since the two qualities, except when measured by instruments, are
difficult to separate). Although a standard series of adjectives exists in the
paper trade — "antique," "eggshell,"
"vellum," "machine," and "English" (for uncoated papers), or "dull,"
"semidull," and "glossy" (for coated papers)[78] — any attempt to employ
these terms
without reference to a visual standard or recourse to numerical
measurement would tend to accentuate the problem of subjectivity. Other
similar series could be formulated — such as "very rough," "rough,"
"medium," "smooth,"
and "extra glossy"
[79] —
without
reducing the difficulty of deciding where the lines between the categories
should be drawn. Besides, would any two bibliographers agree on these
lines, and could even a single bibliographer observe them consistently?
Such considerations render impractical the attempt to establish on this level
any multiterm sequence. Yet it is usually not difficult to secure agreement
that certain papers are "rough" and others are "glossy." The most sensible
course of action, therefore, is to use "rough" to describe uncoated papers
which have a pronounced roughness and "glossy" to describe coated papers
which have an unquestionably shiny surface; for all papers in between,
whether coated or uncoated, one can use "smooth," or possibly no adjective
at all, implying that only wide variations from the norm need be specified.
Such a tripartite scheme does not eliminate subjective judgment but merely
reduces the number of dividing lines where
it must operate. When instruments or visual standards are not to be
employed, it is futile to attempt subdividing a continuum into more than a
few large sections if the results are to convey the same meaning to different
people. For bibliographical purposes, distinguishing "rough" and "glossy"
papers from the broad range in between is usually adequate and
comprehensible; if a bibliographer needs on occasion to employ greater
precision, he should turn to the appropriate instruments rather than increase
his stock of adjectives and intensifying adverbs, which are more likely to
confuse than to refine his description.
[80]
The specification of finish, like that of color and thickness, tends to
have greater significance in connection with machine-made and wove papers
than with handmade and laid papers. Variations in these characteristics in
hand-produced paper, given the nature of the process, may be of little
importance in distinguishing separate runs, whereas such variations in
machine-made paper, with its greater regularity, may be of more
consequence for identification; similarly, precise notation of these properties
in laid (and particularly watermarked) paper may not be especially helpful,
since the chainlines and watermarks generally provide sufficient
identification, whereas such notation for wove (and particularly
unwatermarked) paper may be quite useful,
since there is little else to rely on. Thus the advantages of having detailed
information about these characteristics rarely outweigh the difficulties of
obtaining and utilizing it when the paper under examination is handmade,
laid, or watermarked; for these papers the unsophisticated approach
described here is often adequate. On the other hand, the usefulness of
precise data about these matters may well justify the efforts entailed when
the paper being analyzed is machinemade, wove, or unwatermarked; for
these papers significant differences may be overlooked if precision
instruments are not employed. All one can say is that any bibliographical
description of paper should be expected to take some account of thickness,
color, and finish. For the most part, the techniques used can be quite
simple; but, when the occasion warrants, the bibliographer — aware
of
the more elaborate methods available to him — should not hesitate
to turn
to the laboratory for aid.
