MEDIAThe materials trusted for sketching were quite similar to those employed in the Renaissance. The
growing availability of paper decreased the physical value of the sketch, thus, the sketches could be
rejected and restarted more readily. Graphite was substantially more prevalent, especially after 1662
when it reached mass production in Nuremberg as a form of pencil. Encased in a wooden holder, the
medium substantially gained in popularity because of its convenience. Able to be applied directly to
paper the pencil did not necessitate a prepared surface as silverpoint required. Eventually the graphite
was mixed with clay and mechanically produced (Petroski, 1990 ). Comparable in softness to chalk,
graphite moved smoothly across the surface of the paper. Graphite was also somewhat erasable, in
that the distinct lines could be rubbed off or even intentionally smudged for shading.
Many baroque architects invariably chose to sketch with quill pen and ink. A substantially darker
line (causing greater contrast), readability, and its smooth flow were most likely the reasons for this
medium’s popularity. Ink was permanent, which may have assisted architects to conclude design solu-
tions. In most cases, though, these architects relied upon a variety of media. One medium could be
corrected with another to differentiate an idea from a subsequent thought. A first draft could be laid
out in graphite and alternatives displayed over the top in another medium. Inigo Jones, in the middle
seventeenth century, had scored the paper with guidelines so as not to be distracted by their prom-
inence, or perhaps because he realized the difficulties with erasure. François Mansart and Bernini, for
example, sketched moving quickly between images, not bothering to stop and erase; they recognized
the page of sketches was an entirely personal dialogue. It could be speculated they needed to refer-
ence earlier images and they did not care if the sketches intersected or overlapped. Juvarra, for example,
employed ink wash in such a way that the brush became another sketching tool, rather than pri-
marily a device to render tone and value. With the brush they could vary line thickness or weight from
beginning to end of a single stroke, achieving more expressive images. Piranesi also found etching to
be an accommodating medium for expression, determining it could be continually reworked and
widely distributed throughout the printing process. This allowed him more easily to disseminate his
theoretical propositions.
The seventeenth century witnessed the development of instruments of exact measurement, par-
ticularly those necessary for exploration in astronomy and navigation, as well as military engineer-
ing and land surveying. The documentation required for these endeavors spawned the emergence of
technical drawing. Tools in common use by the 1600 s were scale measures, protractors, compasses,
set squares, and parallel rules. These tools were necessary for the accuracy required of orthogonal
drawings (plan, section, and elevation). Fairly crude ruling pens had been available previous to the
seventeenth century, when composite metals were used to make drawing tools. The non-corrosive
metal instruments were also substantially more precise. Important for draughting a finished solution
these implements often assisted the architect while sketching.
The architects of the baroque period found sketches served their design processes in various
capacities, from the search for form to presentation and evaluation with a client. These sketches
show increasing confidence in the media, evidenced by a substantial number of examples that have
been preserved. Sketches also gained a wider acceptance, being used for such purposes as diagram-
ming, calculating geometries and communicating to draughtsmen.H5719-Ch02.qxd 7/15/05 3:20 PM Page 49