As a parchment maker, this is a question I have to contend with frequently.
These terms seem to be used interchangeably,
depending on who's talking. While one person will insist doggedly on one
set of definitions, another will insist just as doggedly on a different and
Before delving into descriptions of the various types of parchment products
that are available, a little backround might be useful (henceforth,
I will use the term 'parchment' generically to refer to parchment, vellum,etc.).
Parchment is a paper-like material made from (typically) raw, untreated animal
skins that have been un-haired and dried under tension. This is not to be
confused with parchment-paper. Although, in theory,
almost any animal skin can be made into parchment, sheep, calf, and goatskins
are those most commonly used. Parchment is relatively
inelastic and has a firm handle when compared to leather. The 'hair' side
of the skin is that side where the hair was attached, and the
'flesh' side is the side facing the flesh of the animal. If the parchment
is prepared from the full thickness of the hide, it will have a 'grain' layer
on the hair side, with a distinct follicle pattern, as is the case with a
full-grain leather. The flesh side will typically have a smooth, silky
to the boundary between the skin and the underlying layers of connective tissue.
In recent decades, within the trade, the term 'parchment' has often been used in
reference to a lower grade product made from sheepskin splits. The skin is
split into two layers by machine, and the lower layer or 'flesh-split' is
made into parchment. Like suede products, it does not have a grain (the grain
remains on the upper layer or 'grain-split'). Manufacturers have tended
to use 'vellum' in reference to better grades of product regardless of the
animal species involved, and regardless of whether or not that product has
the grain layer removed. (ie. everything that is not made from a sheepskin
flesh-split falls under the name 'vellum')
Others have tended to use 'parchment' as a generic term for all products
except those made from calfskin, for which they reserve the term 'vellum'. They
often justify this on linguistic grounds since it would appear that the word
vellum (and the french 'velin') derives from the latin 'vitellus', meaning calf.
Authorities in the field aren't quite as dogmatic in their approach.
Reed (_The_Nature_and_Making_of_Parchment_, 1975) presents
evidence that, as far back as the middle ages, both terms were being used
to refer to any sort of parchment, without regard to the species involved.
Furthermore, he argues that the word 'vellum' may actually derive from the
latin 'pellis', simply meaning 'skin'.
The impression I get is that in academic circles, this controversy over the usage
of the two terms is regarded as rather tedious, and I tend to agree. My impression
is that conservators and codicologists tend to use the term 'parchment' generically,
and avoid the term 'vellum' since it seems to mean different things to different
Parchment is by no means a uniform product. The look, feel, and behaviour
of the finished product can be affected by such factors as:
1) The species, breed, age, and sex of the animal that provided the skin
2) The general health of the animal and the time of year of slaughter
3) Care taken in flaying and handling the hide before it reaches the parchmenter
4) The parchmenter's treatment of the hide at all stages of manufacture
There is considerable latitude in how a skin can be converted into parchment.
Considering the many variations on the manufacturing process that have been
used over the centuries, and in different places, any rigid categorization
based on the method of manufacture is of questionable validity.
While some variations in the procedure may only lead to subtle differences in
the finished product, others can yield differences that are quite marked.
My own feeling is that, the differences between animal species aside, there are
two broad categories of parchment. On the one hand are parchments that might
be termed 'Full-grain', where the grain layer has been left more or less intact
on the hair side. On the other, we have skins where the grain layer has been
partly or wholly removed (either by splitting or by shaving). Removal of
the grain layer will make the two sides of the parchment more
similar in appearance and texture, will make the hair side more receptive to
inks and paints, and will obviously make the parchment thinner and somewhat
weaker. Since this was, and still is, often done for parchment that is
intended for inclusion in books and will therefore be used on both sides,
this second category might be designated 'manuscript'
parchments. Historically, there probably hasn't been a clear dicotomy, but
rather a continuous spectrum between the two extremes.
In addition, the surfaces of these different parchments might
be further modified in terms of texture and opacity by the use of various
abrasives (eg. pumice) and/or the application of various coatings (eg. size,
chalk, gessoe, etc.).
Whether a particular type of parchment is best suited to the needs of the binder
or the calligrapher is, to some extent, a matter of taste. While a full-grain
parchment would typically be prefered for binding since the grain provides an
abrasion resistant surface and an interesting texture for a book cover,
a parchment whose grain layer had been removed could also be used.
A thin, shaved parchment might be desireable as a spine liner or endpaper
reinforcement. Strips of either sort can serve as sewing supports or endband
cores (alone, or in combination with leather/tawed skin).
Similarly, a calligrapher may wish to use a manuscript (ie. shaved) parchment
for folios in a book, but be content to use the flesh side of an unshaved
parchment for a framed piece that will only be worked on the one side. Or,
they may wish to use the hair side of a full-grain parchment to take
advantage of the texture and pigmentation for a particular effect.
It is unfortunate that the terms parchment and vellum have been used
inconsistently and that such ambiguity with regard to their definitions
persists. In the absence of any standardized descriptive nomenclature,
the prospective user must seek out full descriptions of every product and
examine samples to determine exactly what they are getting. One person's
parchment is another's vellum, and vice versa.
Cains, Anthony. 1992 "The Vellum of the Book of Kells" The Paper Conservator. vol 16: 50-61.
Clarkson, Christopher. 1992 "Rediscovering Parchment: The Nature of the Beast" The Paper Conservator. vol 16: 5-26.
Reed, R. 1972. Ancient Skins, Parchments and Leathers. New York: Seminar Press.
Reed, Ronald. 1975. The Nature and Making of Parchment. Leeds, England: The Elmete Press.
Ryder, Michael L. 1964. "Parchment -- Its history, manufacture and composition" Journal of the Society of Archivists. vol 2: 9, April, 1964.
Thompson, Daniel V. 1936. The Materials and Techniques of Medieval Painting. NY: Constable, 1936.
Visscher, W.P. 1986. "Trends in Vellum and Parchment Making Past and Present" The New Bookbinder: Journal of Designer Bookbinders. vol. 6: 41-81.