Vitreography: laser engraving glass
Guest blogger Hannah Marie Smith
Vitreography is an intaglio printmaking method that uses glass plates as printing matrices. Traditionally 3/8” thick glass is marked with a diamond hand scribe, diamond engraving wheel, sandblasting medium, or any number of resists. The plates can also be marked with an ammonium/sodium bifluoride acid solution, but these processes are toxic and imprecise. All of these approaches have limited the prevalence of vitreography in contemporary printmaking practices because printmaking studios are rarely equipped with wet “cold working” and sandblasting equipment.
In this post I share how CO2 laser cutters can be used to make the technique of vitreography more accessible to students and professionals working in printmaking studios with access to laser engraving systems.
As digital machining makes its way out of the commercial industrial setting into artists' studios, a range of tools—such as laser cutters, CNC routers, and 3D printer—are becoming more accessible. Software and manufacturing companies, recognizing a market gap, have sprung up and since late 2015, affordable laser cutters for home and studio use have been on the market, including Glowforge’s desktop model. In addition, tech/maker spaces have increased access by artist and craftspeople to CO2 laser systems.
With the advent of digital proliferation every day, some members of the fine art/craft communities are adopting such tools and practices into their studios. In sum, these hybrid techniques are allowing practitioners to move into the digital realm in both practice and theory, adopting new tools in the same way that craftspeople have always done.
In the context of vitreography, lasers cutters/engravers have an array of uses that allow one to take digital imagery, both in raster (.JPGS and .TIFF) and vector (Adobe Illustrator and AutoCAD) formats, and etch into the surface of the flat plate glass for intaglio printing.
2. How it Works
Laser (a sleek acronym for Light Amplification by Stimulated Emission of Radiation) operates on the basis of electricity exciting gasses in such a way that photons are released. These coherent photons are then reflected and focused by mirrors into the optic/lenses to cut or mark a material surface. CO2 lasers operate on an infrared wavelength of 9 to 12 micrometers, which can be absorbed by organic materials.
The heat energy of a C02 laser beam can be focused on the flat glass with such intensity that it creates a small circular pockmark on the plate’s surface. These marks are micro-fractures in the surface of the glass. While such a mark is capable of holding ink, it is relatively shallow and does not compare in depth to the mark that sandblasting or engraving tools are capable of making. It's more similar to traditional etching marks in its depth and finesse.
3. Technical Benefits
For printmakers this direct digital to physical mark-making process is particularly successful when combined with the glass plates because it offers an alternative to the challenges inherent in metal or wood plates. Glass is easy to wipe and does not cause pigments such as yellow to change color through oxidation. It is also resilient against compression in comparison to laser engraved wood for intaglio or relief.
Laser engraving also allows for the production of glass printing plates independent of sandblasting equipment and engraving tools that would otherwise compete for studio floor space. While other technologies, such as Ikonis or Rayzist, can be used to transfer digital imagery onto glass surfaces, they don’t allow for the same level of detail and they produce higher levels of material waste than laser engraving. These products also require additional equipment, a space safe from UV light, and additional processing time.
4. Post-digital Printmaking
Within printmaking, these studio technologies fall into a category of "post-digital printmaking," a term coined by Paul Catanese and Angela Geary. Post-digital printmaking can be understood as “a distinct area of printmaking practice ...Radically different from digital print production (inkjet on high-quality paper), Post-Digital Printmaking integrates Computer Numeric Control (CNC) devices such as laser cutters and CNC routers with matrix production for lithography, intaglio, and relief. This contemporary practice incorporates the strengths of both digital and (hand-printed), resulting in hybrid...techniques.”
Overall, laser engraving for glass printmaking plates is a process that leads to unique image management, studio workflow, and printed impression. Like all glass plate printmaking, it is not practical for many printmakers. But laser engraving glass plates offers much in terms of digital to physical image translation, unique printing matrices, the materiality of images, and accessibility.
Hannah Marie Smith's practice combines performance, photography, tracing, cutting, carving, and casting to explore the intersection of complexity and understanding. She was graduated from Plymouth State University, New Hampshire with a BFA in Printmaking. Introduced to glass through vitreography, cold working, and kiln forming during an internship at Squam River Studios, also in New Hampshire, she has gone on to manage the print shop at Pilchuck Glass School. There she works with Artists in Residence in the production of prints for their permanent collection. She has been an artist in residence at The Holderness School, Grin City Collective, Pyramid Atlantic Art Center, and the University of Texas in Arlington. Her work has been shown throughout New England, including shows at 808 Gallery in Boston. Currently she is exhibiting and teaching workshops nationally.
 Catanese, Paul and Angela GearyPost, Digital Printmaking: CNC, Traditional and Hybrid Techniques. London: A&C Black, 2012.