|All early maps are printed in black and white: the British Ordnance
Survey maps were not printed in colour until as late as the 20th century.
The difficulty was to obtain the correct register, that is the exact placing
of each individual colour, to avoid either overlapping or a gap between
two adjoining colours. In either case the result is most unsatisfactory.
In the middle of the 18th century George Baxter perfected a colour printing
process using a series of blocks, one for each colour, with the correct
register. His method was a closely guarded secret, and he obtained
a very high standard of work, probably by destroying any print which was
not entirely to his satisfaction. His prints were Victorian sentimental
subjects and he was not concerned with maps, but his techniques were handed
down, and it was through his inspiration that colour printing began.
Many of the maps published in black and white were subsequently coloured
by hand and rather more original colouring was carried out than is generally
supposed. (It is sometimes thought that such maps have all been coloured
in recent years.) In many cases it is very difficult, even for an expert,
to establish whether or not the colouring of a particular map is old.
In the main it is most desirable to acquire maps which are in original
colour, but some old colouring is very poor, is crudely applied, inappropriate,
and garish, carried out with insufficient attention to detail.
|In most cases the colour enhances the map and makes it easier to read,
one of the reasons why they were coloured in the first place. Though
the colourist had a free hand to colour the map as he wished, there was
a kind of formula which was normally followed by the professional.
Each colourist mixed his own colours and had his own techniques for their
application. Various materials were used as size to prevent the paper
absorbing the colour too rapidly or unevenly, white of egg being the most
common. judging from books on the subject, some colourists went to great
lengths to obtain the correct colour, the constituents coming from all
over the world and taking several days to prepare. These colours
are generally remarkably good, retaining their brilliance and showing little
sign of fading since they were applied. The greens can cause some
trouble: they were made from verdigris which in time rots through the paper
to the extent of disintegration. This occurred mainly with the maps
which were coloured before 1700, and if there is any doubt about the strength
of the paper which has been coloured in this way, it is advisable to have
the paper strengthened from the back, not a difficult operation and one
which may save the paper from cracking.
The standard procedure was to begin by colouring in the boundary lines, a different colour being applied on either side of the line. Sometimes each division is coloured in a pale wash. Estates, parks and woods are coloured green, seas and rivers in blue, hills in brown or occasionally in green, and the cities and towns in red. The extra decoration is coloured as naturally as possible, animals, humans, shipping and all the things that appear in the cartouches. Sea monsters are usually green, their large mouths coloured in red, but this was entirely left to the imagination of the colourist. Mistakes can easily occur. One particular map of the County of Cheshire, famous for its cheeses, shows whole cheeses in the cartouche looking like huge millstones, coloured in unappetising magenta and blue.
|The armorial shields, of course, had to be coloured correctly,
and this was done by following two simple codes, either by a guiding letter
or by a system of engraving the background of the shield. The traditional
names for each colour are derived from mediaeval French. Gules (red)
was marked G, or the engraved lines were vertical. Bleu (blue) was
indicated by B, and had the lines engraved horizontally. Sable (black)
marked by S, or by lines engraved both horizontally and vertically.
Vert (green) was lettered V, or the lines were engraved diagonally from
top left to bottom right.
Purpure (purple), an unusual colour in heraldry, was lettered P, or
had engraved lines crossing from top right to bottom left. Or (gold)
is lettered 0 and the engraving is geometrically dotted. Argent (silver)
lettered A, is left plain and is not usually coloured on old maps.
The system worked very well, an easy guide for the professional colourist
who knew the code, but not all colourists were professionals and sometimes
the armorials are incorrectly coloured. The Dutchmen unfortunately
reversed red and blue, the two most important colours in heraldry.
This would not have mattered had all Dutch maps been coloured there but
many of them have been coloured elsewhere, according to the usual code.
|Colouring is still being added to maps today, generally speaking with
great care and consideration by experienced colourists who know the right
colouring for each map-maker. Often their work is preferable to that of
the early colourists. Whether this practice is aesthetically right
or wrong has been the subject of many long discussions. There are
some maps which were not intended to be coloured: the Italians thought
that colouring obscured the detail and the quality of their engraved work.
There are other maps which lend themselves to colour, particularly the
plainer maps of the 18th century and those which are crowded with detail.
As a rule it is best for the buyer to use his own discretion: the main thing is that he should like the colouring himself. The dealer cannot assist over this, nor can he always state categorically the period at which the colouring was applied.