C.S. POGUE

‘Liquid Asphaltum’ is an emulsion of two primary components—the ‘Asphalt’ component, which is the sticky, viscous, semi-solid active ingredient that forms an ink-receptive film over image areas—and the “Liquid” component, which is the petroleum distillate used as a vehicle to apply the asphalt and then evaporate. The ‘Asphalt’ component has several possible sources—the ‘bottom of the barrel’ from the refinement of crude oil; the thick viscous liquid derived from tar sands; or the mineral Gilsonite, a bitumen-rich ore mined in Utah. Asphalt has a somewhat variable chemical composition, depending on its source.

The ‘Asphalt’ component is a relatively stable material until heated, as on a hot plate or with a hair dryer, when volatile vapors and gases including toxic hydrogen sulfide can be released.

The ‘Liquid’ component is a medium petroleum distillate capable of keeping the ‘Asphalt’ in suspension while in storage and during application. After application it must evaporate at a reasonable rate to leave the film of ‘Asphalt’ behind. According to the Material Safety Data Sheet for ‘Senefelder’s Liquid Asphaltum’ the liquid component is “Mineral Spirits/Xylol”. ‘Xylol’ is a term for Xylene, also known as Dimethylbenzene when it is used as a solvent. Like many petroleum-based material, its vapors are a moderate irritant to lung tissue, and a foreign material to the body’s metabolic processes.

Both components are not highly-purified compounds, but rather are mixtures of similar hydrocarbons, depending on the sources and refinement processes.

D & S BioLaq is a high-functioning substitute for both Liquid Asphaltum and Red Lacquer V used in lithographic and intaglio printmaking applications. It is 100% bio-based, biodegradable and contains no materials harmful to the environment. It consists of a durable film-forming material (the ‘Laq’), taking the place of ‘Asphalt’, and a bio-degradable solvent, BioSolut. Both components are listed by the FDA as suitable for use in pharmaceuticals, and millions of people ingest the pharmaceutical grade of the ‘Laq’ component every day as an enteric coating on their low-dosage aspirin and many other drugs. Unlike Shellac, BioLaq does not contain toxic methanol added as a ‘denaturing’ agent to the ethanol solvent in conventional Shellac.

D & S BioLaq is a durable ink-receptive layer for image areas in lithography and functions as an excellent brush-on hard ground for intaglio plates, in addition to a stop-out when simply evaporated down by 1/3 to increase thickness. It can also be used for long-term storage protection of image areas on lithographic plates and stones. When ready to print, simply wipe the image areas with a little soybean oil or BioSolut on a clean wipe to revive ink receptivity.

D & S BioLaq is available from Graphic Chemical & Ink, and from Renaissance Graphic Arts. There are no Hazmat shipping charges on D&S products! For more information, visit www.CSPogueGraphics.com. Why not try some in your studio soon?