Page 316 - Green - Maritime Archaeology: A Technical Handbook. 2nd ed

Chapter 11: Artifact Drawing 295 III. DRAWING MATERIALS
A. FILM
There are several types of drawing surfaces, e.g., transparent, semi- transparent, and opaque. Most drawing suppliers will have sample catalogs of the range of drawing surfaces, so that it is possible to make a selection to suit a particular need and a particular budget. The transparent and semi- transparent surfaces usually have a plastic base (polyester or acetate) and are referred to as film. There are several types available. Plastic drawing film is usually available in a variety of thicknesses and in a transparent (clear), single-sided, semi-matte or double-sided, semi-matte finish. The transparent film is useful for drawing details of objects that can be traced through the film. Thus, copying from photographs or tracing ship’s timbers are examples where detail needs to be seen through the drawing surface and maximum clarity is therefore required. With this shiny, clear plastic, the surfaces have to be kept clean and free of grease. The type of pen and ink selected must give an even, dense line which takes well to the surface. Alcohol-based, fiber-tipped pens seem to work best on this drawing material.
The matte or semi-transparent materials are excellent for line drawings and illustrations. Ink mistakes can be repeatedly scraped off using a scalpel or a damp rubber. Care should be exercised not to damage the surface excessively, as this can cause the ink to run along fine scratches. The mate- rial is dimensionally stable and, most important, completely waterproof. This is often essential when working in the field, as drawings often get wet or can be splashed or affected by extremes of humidity and dampness.
There are, however, some important disadvantages attached to using matte or semi-transparent film. The surface is prone to pick up grease, par- ticularly from the illustrator’s hands. When drawing, it is necessary to keep hands scrupulously clean and it is preferable to work with one’s hand on a paper tissue. If grease gets onto the surface from a thumbprint, for example, the ink takes differently to the surface, causing uneven lines. It is, therefore, essential to prepare the surface prior to inking by treating it with inking powder. Also, plastic surfaces are not as porous as other surfaces and there is a tendency for the lines to fade; thus, if the pen is giving an uneven flow, the line density varies from thick black to a gray where the surface shows through. This creates formidable problems when photographing the drawing for reproduction. Also, where the lines or ink surfaces are thick, the ink tends to be shiny causing reflection problems in photography. Plastic film takes a long time to dry, particularly in high humidity conditions. Thus, very great care must be taken not to smudge wet lines, and ink lines must