4 OTHER MATERIALS USED BY MEDIEVAL PERSIAN PAINTERS

4.1 VEHICLES, SIZES, AND ADHESIVES

IT IS important to note that the information in this section is a compilation of the literary evidence only. No analytical work was done on the media. Materials with adhesive properties like vehicles and paper sizing can be most conveniently divided into four groups: proteinaceous materials including gelatin, glue, egg yolks, and egg whites; starches from rice or wheat; vegetable gums; and waxes and oils.

Schulz (1914, 22) has suggested that gelatin, a highly purified form of glue, was employed as sizing for some paper in Persia. Without providing convincing evidence, other scholars have postulated the use of glue as a binder for many pigments in Persian painting (e.g., Behzad 1939). The writer of Qadi Ahmad's appendix mentioned glue as a binder for gold pigment. He also indicated that egg yolk was employed as a vehicle for some pigments (Minorsky 1959). Schulz (1914, 23) has speculated that egg white might have been employed to prepare the surface of writing paper.

Hunter (1978, 194) claimed that starches were the most commonly used sizes in Persian papermaking. Wheat starch cooked in water to make paste was required for laminating papers and for inlaying miniature paintings as well (Grohmann 1967, 126).

The appendix to Qadi Ahmad's treatise discusses the addition of gum (arabic) as a vehicle for many pigments (Minorsky 1959). Grohmann (1967, 128–29) has carefully documented the use of gum arabic as a vehicle for black and colored inks. Such convincing evidence supports the notion that gum arabic (From Acacia senegal) constituted the essential component of the medium employed in most miniature paintings of the 15th and 16th centuries. Gum tragacanth, which swells considerably in water, could have provided an alternative adhesive to starch pastes, according to Grohmann.

A number of scholars have suggested that, in addition to the aqueous base of gum arabic, the vehicle used in Persian painting must have included one or more materials to impart greater flexibility and durability to the paint films. One such combination, wax and gum arabic, postulated by Laurie (1939) as the binder in Persian painting, has handling characteristics and a finish that probably would not have met the requirements of the Persian painter. Grohmann (1967, 128) commented on the addition of linseed oil. One can still find the addition of oil to gum mentioned in modern literature on artists' techniques as a method of strengthening the medium (Mayer 1970). Another combination suggested by Martin (1912, 108) includes glue. Persian miniaturists could have added a variety of other materials to particular pigments in combination with the vehicle. Honey and sugar, due to their hygroscopic qualities, when combined with gum arabic solution, might provide flexibility (Mayer 1970). Grohmann (1967, 129) has mentioned the addition of pomegranate juice to cinnabar. No doubt throughout the period under consideration Persian artists employed several variations of the basic medium, depending on availability of materials and changes in technique.

4.2 DRAWING AND PAINTING IMPLEMENTS

According to the literature, the Persian artist used a charred twig, possibly of tamarind, for drawing. Powder from the charred twigs for pouncing and a finely pointed awl (minfad) for punching holes through the paper were both important to the Persian technique of copying (Martin 1912, 103; Grohmann 1967, 126).

According to Grohmann (1967, 126), calligraphers (and possibly painters), filtered the dust and other unwanted particles from their inks (or paints), by saturating a lump of cotton wool with color (liqa) from one palette and transferring it to another by squeezing the color from the wool with a conoid, ebony rod (milwag). During the painting of a manuscript illumination or an individual painting, the paper was secured to a portable, smooth wooden panel with a clamp (Welch 1972, 26). The painting technique depended on extensive burnishing. Polished agate, rock crystal, or carnelian could have served as the burnisher (Martin 1912, 108; Behzad 1939). The bristles of the painter's finely pointed brushes probably consisted of either the hairs from the throat of a Persian kitten or the hairs from the tail of a squirrel (Behzad 1939).

Behzad (1939) has described a method for making brushes that might have been followed in Iran. Hairs for brushes were collected and floated on water to separate them. They were then laid on a smooth, slick surface such as a faience slab. When dry, they were gathered with a silk thread, fitted directly into the quill opening, and secured. According to Behzad, the painters preferred the first three feathers of the pigeon's wing for the production of brush handles. Sadiqi Bek gave an elegant description of the making of a brush from squirrel's fur. The hairs from the squirrel's tail were combed, sorted according to length, and then tied together with three separate knots (Dickson and Welch 1981).

4.3 PAPER

Paper was manufactured in Iran perhaps as early as the 8th century. The Arabs learned the craft, so the story goes, from Chinese craftsmen (Vajifdar 1981; Pedersen 1984, 61). Rag papers, or papers made from linen fibers, were available as well as silk papers. Locales known for their paper production were Samarkand, Zasim Beg, and Tabriz as well as sites in India and China (Vajifdar 1981). Pedersen (1984, 64) also notes Baghdad and Egypt as places where paper was made as early as the 12th century. Paper made in Tabriz was characterized by a yellowish color, according to Farooqi (1977). All paper was not necessarily from rags, however. An 11th-century description of papermaking from plant fibers mentions a quicklime process for softening raw fibers (Bosch et al. 1981, 28). Snyder (1988) found evidence in the papers that she examined of both rag and plant sources for the paper fibers. In Islamic paper, the mold left laid lines in the paper but not chain lines because the horsehair thread used to stitch the mold together did not leave impressions in the paper (Snyder 1988). Watermarks, common in European papers, are not found in Islamic papers (Bosch et al. 1981, 30).

All the paintings in this study were executed on burnished paper. Snyder (1988) found inclusions in the papers she studied that might have been introduced in the papermaker's vat or during the burnishing process.

The majority of paintings in this study were on thin, fine paper. In this context, “fine” denotes a paper with very few incompletely beaten fiber inclusions. One painting was on a thicker sheet of paper that was equally fine. Four paintings were on sheets of coarser paper, implying that the paper contained small, uneven clumps of paper fibers. Not all the paintings were done on a single sheet; four were on layered paper. All the papers were a creamy white color, and only one had been decorated with flecks of gold prior to the application of paint. None of the paintings in this survey were on tinted paper, although tinted paper was used in Persia, (Bosch et al. 1981, 34).

In this discussion a concerted effort has been made to include all possibilities and to indicate which materials and implements were most probably employed. With additional technical research, such as the pigment analyses reported here and others mentioned in the pigment section of this paper, future discussions of Persian painting will benefit from a more substantial base of documented information.