Hand Gravures
I placed this article here pending creation of another category area for chemicals and attributes. -jcm
Low Tox / No-Tox approach to etching with copper
by John C. Murray
Ferric chloride has proven to be a far less harmful alternative etchant than traditional nitric acid. For one thing, ferric chloride is a corrosive, rather than an acid. This means it will not penetrate and burn your skin when you come in contact with it. It will, however, turn your skin a bright yellow and will also stain your clothing-or anything else it touches-with that same cheerful color. Remember to use eye protection when handling this chemical; it is also a good idea to have an eyewash station nearby or running water to flush the eyes. Ferric chloride works best with copper plates to give a nicely etched line. Until recently, copper plates could only be etched in a specially made vertical tank in order to allow oxidized residues to slough off and fall away from the line work when using ferric chloride by itself.
Copper plate etching became radically better with the introduction of the Edinburgh etch, which combines anhydrous citric acid powder with ferric chloride. Edinburgh etch cut etching times by almost one half, and gives a razor-sharp and surgically clean line, all without having to use a vertical etching tank. Because the Edinburgh etch solution consumes the material oxidized from the line work on the plate with no accumulating residue, the plate can be etched horizontally in a tray oriented face up. Additionally, unlike etching zinc plates in nitric acid there are no bubbles to "feather" away because none are produced. Other than normal ambient circulating room air, no additional venting is needed because there are almost no fumes or odors when etching.
Copper plates have been shown to etch more cleanly than zinc using the Edinburgh etch and are also more durable, holding up to the considerable pressures of the intaglio press bed. For drypoint work, copper is a clear winner because it is a more uniform and ductile metal, allowing the stylus to incise and move across the plate more smoothly and freely than does zinc. While copper may be an expensive metal, I have found that using roofing copper is satisfactory for all types of intaglio work, including mezzotint. Roofing copper is softer than commercially available engravers copper, but experience has shown it to be sufficiently strong to allow editions of more than twenty drypoint or even mezzotint prints and fifty or more traditionally etched prints. Roofing copper is thinner than engravers plates, and this may limit the plate size to less than 11 x 14 inches. With these limitations in mind, the price offset for using roofing copper places this alternative material at less than the cost of zinc plates. I buy flat, pre-cut 5 x 7 inch copper step-flashing from a local roofing supply company, and each piece (plate) costs me about $4.00. (Two years ago, that same 5x7" copper flashing plate cost about $1.00. Tremendous increase in very little time.) Now, go look up what the going rate for the same size plate in thicker engravers copper is from your friendly graphic supply source, and you will see why we should all be excited about using roofing copper.
Philosophical thought---
Earlier in my printmaking career, I was impressed with how many images could be printed from a plate and therefore tended to create and print up large editions. This quickly turned my studio into a storage facility, and I was straddled with the care and maintenance of an ever-expanding inventory of unsold prints, not quite what I had in mind as a printmaker. By keeping editions less than 20 prints, the work continues to be classified as “fine art” rather than mass produced posters. Current thinking points toward the opinion that any edition that has more than 100 images is no longer to be considered "fine art". It is beginning to look ever so much as a mass-produced image with diminished value to a serious collector.
A far better approach is to have “sold-out” editions, and besides that-it forces me to continue working at what this is all about: printmaking.
-JCM
=================================================
Low Tox / No-Tox approach to etching with copper
by John C. Murray
Ferric chloride has proven to be a far less harmful alternative etchant than traditional nitric acid. For one thing, ferric chloride is a corrosive, rather than an acid. This means it will not penetrate and burn your skin when you come in contact with it. It will, however, turn your skin a bright yellow and will also stain your clothing-or anything else it touches-with that same cheerful color. Remember to use eye protection when handling this chemical; it is also a good idea to have an eyewash station nearby or running water to flush the eyes. Ferric chloride works best with copper plates to give a nicely etched line. Until recently, copper plates could only be etched in a specially made vertical tank in order to allow oxidized residues to slough off and fall away from the line work when using ferric chloride by itself.
Copper plate etching became radically better with the introduction of the Edinburgh etch, which combines anhydrous citric acid powder with ferric chloride. Edinburgh etch cut etching times by almost one half, and gives a razor-sharp and surgically clean line, all without having to use a vertical etching tank. Because the Edinburgh etch solution consumes the material oxidized from the line work on the plate with no accumulating residue, the plate can be etched horizontally in a tray oriented face up. Additionally, unlike etching zinc plates in nitric acid there are no bubbles to "feather" away because none are produced. Other than normal ambient circulating room air, no additional venting is needed because there are almost no fumes or odors when etching.
Copper plates have been shown to etch more cleanly than zinc using the Edinburgh etch and are also more durable, holding up to the considerable pressures of the intaglio press bed. For drypoint work, copper is a clear winner because it is a more uniform and ductile metal, allowing the stylus to incise and move across the plate more smoothly and freely than does zinc. While copper may be an expensive metal, I have found that using roofing copper is satisfactory for all types of intaglio work, including mezzotint. Roofing copper is softer than commercially available engravers copper, but experience has shown it to be sufficiently strong to allow editions of more than twenty drypoint or even mezzotint prints and fifty or more traditionally etched prints. Roofing copper is thinner than engravers plates, and this may limit the plate size to less than 11 x 14 inches. With these limitations in mind, the price offset for using roofing copper places this alternative material at less than the cost of zinc plates. I buy flat, pre-cut 5 x 7 inch copper step-flashing from a local roofing supply company, and each piece (plate) costs me about $4.00. (Two years ago, that same 5x7" copper flashing plate cost about $1.00. Tremendous increase in very little time.) Now, go look up what the going rate for the same size plate in thicker engravers copper is from your friendly graphic supply source, and you will see why we should all be excited about using roofing copper.
Philosophical thought---
Earlier in my printmaking career, I was impressed with how many images could be printed from a plate and therefore tended to create and print up large editions. This quickly turned my studio into a storage facility, and I was straddled with the care and maintenance of an ever-expanding inventory of unsold prints, not quite what I had in mind as a printmaker. By keeping editions less than 20 prints, the work continues to be classified as “fine art” rather than mass produced posters. Current thinking points toward the opinion that any edition that has more than 100 images is no longer to be considered "fine art". It is beginning to look ever so much as a mass-produced image with diminished value to a serious collector.
A far better approach is to have “sold-out” editions, and besides that-it forces me to continue working at what this is all about: printmaking.
-JCM
=================================================
Reprinted from "In Print", Newsletter of the Maryland Printmakers, Inc.
Technical Notes from
Maryland Printmakers President, John C. Murray
Fluorescent Type UV Exposure for ImagOn
Question: Has anyone at Maryland Printmakers used fluorescent type uv exposure with ImagOn? Howard seems to think it won't work, only a point light source does the job. What is your opinion?
Pictured here is a 4 plate 4 color acrylic photopolymer gravure. Photopolymer film was laminated to copper support plate, exposed with a NuArc 26-K1 1,000 watt Ultraviolet Exposure unit. Printed on dry Zerkall Copperplate paper using AKUA Intaglio waterbased inks. Source material is a digital photo that has been modified with Photoshop. The subject is the Dragon Boats in Baltimore Harbor. Colors are a lot "punchier" when printed dry, and the yellow waterbased inks don't turn green on copper plates!
Technical notes offered by Maryland Printmaker, John Murrray:
A couple of years ago, we went through the task of finding an answer to this same question concerning exposure unit light sources. I was planning on building a unit. The single point light source will provide the cleanest and most complete rendering of (especially) fine lines from your original transparency material. Accurate and complete rendering when exposing your art work depends on having the exposed areas harden when struck by UV light, and anywhere there is a line or non-white area, there is in effect a shadow or blockage of the UV light which is not hardened. When developed, the unexposed areas slough away, leaving areas that will hold ink. Having a sandwich of transparent film on top of the Imagon coated plate, including and because of the thickness of the transparent material itself, means that some light can sneak in from the sides of the drawn lines and undercut that drawn line, by hardening the Imagon Ultra film immediately underneath the line. This is because there is light coming in from multiple directions. Fluorescent tubes work very well for exposing silkscreens, but not so for intaglio plates.
The single point light source will not allow light to sneak in from the sides or underneath the margins of the lines--the single point light it will cast a sharply defined shadow and block the UV light wherever there is a line of artwork (similar to the sun). When developed, the line will be as complete and as distinct on the Imagon Ultra film as it is in the original art on the transparency film. Light coming in from other than a single point will come in from the side and diminish the quality of your image when the plate is developed.
The single point light source will definitely give you a better result. Fine lines and details will suffer most dramatically from a soft or diffused light source. Your shading and aquatint will not be as dark as it should be.
Also, make sure you are using a vacuum frame to press the transparency (or Mylar film) artwork flat and tight against the Imagon laminated plate. After a lot of reading and research, our group of 4 printmakers chipped in $250 each, and we bought a NuArc 26-1K Metal Halide exposure unit with an integrated UV photodetector cell. It has a digital numeric touch pad for entering a value that represents the number of UV light units for a given exposure. As the lamp deteriorates over time, and the UV output becomes less, the photodetector cell will tell the circuitry to extend the amount of time for the exposure to compensate for the reduced UV light output. This is a very good feature to ensure you have repeatable exposure results. Just using time for calculating your exposures is not nearly as accurate, and you will be constantly recalibrating your exposures to get the desired exposure result. Our NuArc unit has a built in vacuum frame, and does produce about 23 lbs of vacuum, which is sufficient for accurate rendering of the artwork.
==============================================
Technical Notes from
Maryland Printmakers President, John C. Murray
Fluorescent Type UV Exposure for ImagOn
Question: Has anyone at Maryland Printmakers used fluorescent type uv exposure with ImagOn? Howard seems to think it won't work, only a point light source does the job. What is your opinion?
Pictured here is a 4 plate 4 color acrylic photopolymer gravure. Photopolymer film was laminated to copper support plate, exposed with a NuArc 26-K1 1,000 watt Ultraviolet Exposure unit. Printed on dry Zerkall Copperplate paper using AKUA Intaglio waterbased inks. Source material is a digital photo that has been modified with Photoshop. The subject is the Dragon Boats in Baltimore Harbor. Colors are a lot "punchier" when printed dry, and the yellow waterbased inks don't turn green on copper plates!
Technical notes offered by Maryland Printmaker, John Murrray:
A couple of years ago, we went through the task of finding an answer to this same question concerning exposure unit light sources. I was planning on building a unit. The single point light source will provide the cleanest and most complete rendering of (especially) fine lines from your original transparency material. Accurate and complete rendering when exposing your art work depends on having the exposed areas harden when struck by UV light, and anywhere there is a line or non-white area, there is in effect a shadow or blockage of the UV light which is not hardened. When developed, the unexposed areas slough away, leaving areas that will hold ink. Having a sandwich of transparent film on top of the Imagon coated plate, including and because of the thickness of the transparent material itself, means that some light can sneak in from the sides of the drawn lines and undercut that drawn line, by hardening the Imagon Ultra film immediately underneath the line. This is because there is light coming in from multiple directions. Fluorescent tubes work very well for exposing silkscreens, but not so for intaglio plates.
The single point light source will not allow light to sneak in from the sides or underneath the margins of the lines--the single point light it will cast a sharply defined shadow and block the UV light wherever there is a line of artwork (similar to the sun). When developed, the line will be as complete and as distinct on the Imagon Ultra film as it is in the original art on the transparency film. Light coming in from other than a single point will come in from the side and diminish the quality of your image when the plate is developed.
The single point light source will definitely give you a better result. Fine lines and details will suffer most dramatically from a soft or diffused light source. Your shading and aquatint will not be as dark as it should be.
Also, make sure you are using a vacuum frame to press the transparency (or Mylar film) artwork flat and tight against the Imagon laminated plate. After a lot of reading and research, our group of 4 printmakers chipped in $250 each, and we bought a NuArc 26-1K Metal Halide exposure unit with an integrated UV photodetector cell. It has a digital numeric touch pad for entering a value that represents the number of UV light units for a given exposure. As the lamp deteriorates over time, and the UV output becomes less, the photodetector cell will tell the circuitry to extend the amount of time for the exposure to compensate for the reduced UV light output. This is a very good feature to ensure you have repeatable exposure results. Just using time for calculating your exposures is not nearly as accurate, and you will be constantly recalibrating your exposures to get the desired exposure result. Our NuArc unit has a built in vacuum frame, and does produce about 23 lbs of vacuum, which is sufficient for accurate rendering of the artwork.
==============================================
