About Green Mountain Plates
The Green Mountain Plate has some unique qualities as a photopolymer plate. And these qualities are compatible with “direct to plate”, “two-step exposure”, and simple “solar-plate” processes.
Green Mountain Plate is the most tonally sensitive plate on the market, meaning that it has the widest reproduction scale of grayscale information. This tonal sensitivity is due in part to its lower exposure speed and to the consistency and quality of its photopolymer, as well as the process used to apply the photopolymer to the steel. It is a very high quality product.
In the world of emulsion-based photography, lower ASA or ISO determined the acuity and sensitivity to tonal modulation of film. Panatomic-X was an example of a very low exposure speed film that produced finer grain than others and smoother tonality.
For direct to plate, Green Mountain Plates unique photopolymer permits the use of light black inks even when printing at 2880dpi. This is a plate that many of the available workflows using color inks could be customized to take advantage of the higher fidelity of the Green Mountain Plate. Or anyone struggling to print 2880dpi on other plates will be able to on the Green Mountain Plate. We support multiple ink printing with the Piezography three-ink direct to plate system. At Cone Editions Press they are using 10 shades of ink with an in-house process, something unheard of in the world of direct to plate printing. Their online printing services use three or four shades of ink and you can purchase ready to print plates from Cone Editions here. It's a great way to see if direct to plate can benefit your workflow.
For two-step exposure, halftone or mezzotint screens of 1800dpi could easily be used (if they can be supplied). And continuous-tone through the screening more achievable.
For solar plate printing from hand painted positives you will benefit with the tinier grain structure of thinned painting mediums or the addition of any tiny particles in your painting medium so that gradations are easily produced. Diatomaceous earth comes to mind.
Because Green Mountain Plates have a slow exposure speed, exposure times may be 7-10 times longer than competing plates. It will permit you to handle them longer in low UV light situations and you will find that if you have low UV lighting you can work in a brighter studio condition or without the fast fogging of conventional plates. InkjetMall sells verifedUV exposure systems that are the fastest on the planet (generally 4-10 times faster than competing systems).
Green Mountain Plates have a phototropic green dye that turns yellow after final curing of the plate, but turns bright yellow green at its optimal exposure time. Running a simple exposure step wedge will allow you to find your optimal exposure time.
The protective layer over the Green Mountain Plate is not for UV protection but instead to prevent the plate from drying out which causes premature hardening. Remove it shorty before exposure.
Store these plates in a simple darkroom paper safe or keep them in the opaque black plastic they ship in. Keep from extremes of heat and cold. When stored safely their sensitivity will remain for years.