Tuesday, March 19, 2013

Century Plates- Senior Research Project

(This post is going to focus heavily on technical aspects of lithography. You've been warned.)

The plate on the press after roll-up
In addition to the near constant visiting artists and editioning in my spare time I’ve been working on my senior research project. Each Tamarind master printer candidate chooses a subject that they will study and write a report on during their training period to be completed in addition to working with artists. Around the time I started Dwight Pogue from Smith College in Massachusetts had mailed us a few Century Plates to try out. Century Plates are a relatively new product Pogue has been developing for some time that are thicker than aluminum plates, available in a variety of sizes, and are supposed to be re-grainable hundreds of times and hold all the detail of a regular ball-grained aluminum plate. Needless to say, this would greatly reduce on the cost (especially to students) while doing multiple run lithographs and at the cost of nearly one aluminum plate they practically pay for themselves. Pogue and his students have been testing the plates for some time now using Pogue’s other products to process the plates (namely, BioSolut as a replacement for lithotine and acetone, and BioLac for a shellac/lacquer base). I wanted to make sure that traditional materials like lithotine and traditional shellac worked just as well. 

What is also pretty awesome about these plates are the three different ways they can be resurfaced to hold images. The plate can be “renewed” by removing the old image with lithotine, rubbing with Bar Keeper’s Friend for a few minutes, rinsed, and rubbed with an abrasive sponge with a little pile of each kind of grit (80 through 220), and abrading the surface to make the plate like new. It can be “restored” by removing the old image with lithotine, and rubbing with Bar Keeper’s Friend, rinsed, and rubbing with just the abrasive sponge (80 to 220 grit depending on what kind of image is desired). It can also be “refreshed” by removing the old image with lithotine, and rubbing with Bar Keeper’s Friend.

Material tests on the plate before etching and first roll-up

My plan is to try each type of resurfacing with a variety of drawing material: Korn’s pencil 1-5, Stone’s pencil 1-5, Korn’s crayons 0-5, autographic ink, Stone’s tusche concentrate with a dark, medium and light wash, Korn’s rubbing crayon in hard, medium and soft, spray paint, sharpie marker, and industrial sharpie marker. The same materials will be used on each resurfacing, starting with a “renewed” surface, with a small edition (20 sheets) being pulled in black with a leather roller, and again in red using a composition roller. 

So far I’ve tried the “renew” method, since the plate that I received was new without an image on it, I cleaned and grained it according to Pogue’s method just to ensure it was at a proper “renew” state. My first concern was how incredibly smooth the surface was, despite ‘graining’ it. I knew immediately that water retention was going to be a challenge, especially at Tamarind, which not only is in a desert, but also has a ventilation system that keeps fresh air circulating.  My first etch was straight tannic acid, moved around for a few minutes before being buffed in. After an hour the ink was removed with lithotine and put into a butyl based shellac that we’ve been using at Tamarind with success for a few years.

When I rolled up the image I was very pleased with how the pencil and crayon bands looked. The spray paint and rubbing crayon all went darker, but I wasn’t too concerned, as that’s pretty typical for those materials. I had, during mixing, ruined the tusche washes, so I wasn’t too concerned with those, except for the concentrate flat area. Overall, I was pretty impressed. I etched it a second time using more traditional method, since those few areas did go a little dark- gum Arabic over the lights, 50/50 over most of it, and Tapem over the darks. The areas that had gone dark I etched with Tapem mixed with a few drops of phosphoric acid. 

The true test, however, came in printing the edition. I wanted to make sure the edition held up during printing, didn’t gain or go dark in areas, and didn’t scum in the non-image areas. The first few impressions I pulled looked good except for the darkest areas, which appeared salty. I upped my pressure a little, added a little more ink, a few more passes in the dark area and eventually got it to print full. As I suspected I was also having a lot of problems with the plate drying out extremely quickly. I ended up having to use a good amount of glycerine in the water to relax it and reduce the dry out time on the plate. I did notice, too, that the more impressions I pulled, the more the light areas of my plate were gaining. A quick rub of the area with my fingertip cleaned it up, but it was a pretty continuous battle, even with a little 50/50 in my water bowl. About half way through the edition, and after talking with Pogue, I massaged the plate with some tannic acid to try and clean up the light areas. It seemed to help a little in the lightest areas, but the mid-to-light areas were still a little bolder than the original drawing and the first few impressions I pulled. 
The images to the side illustrate three sheets pulled from the edition- number 2 (top or left), number 10 (middle), and number 18 (bottom or right). Number 2 indicates most closely what the original plate looked like after the initial roll up, number 10 illustrates the light areas gaining the most before the massage with tannic acid, and 18 illustrates how the tannic acid had improved the lightest areas. 

After pulling the twenty sheets in black ink, I changed out my slab for a Hanco Master Palette Dark Red. Overall, the results were pretty similar to the end of the black edition after the tannic acid massage. I still had some areas where it tended to gain (click for a larger view), but nothing too serious. 

The ghost image on the "refreshed" plate
After the edition was pulled in the red ink I decided to go to a “refreshed” state by removing the ink with lithotine, acetone and denatured alcohol to remove the butyl shellac base, and rubbed the plate with Bar Keeper’s Friend. The previous image was still a little bit visible, but I wouldn't say it was enough to perfectly trace over. I transfered my previous grid and laid down the same materials as the first test.

I etched all the materials with tannic acid right before leaving Albuquerque. I'm really curious to see how this "refreshed" plate prints, and if the previous shellac base interferes with the new material. 

At the moment I'm sitting in Chicago in a Starbucks, only a day away from the SGCI conference in Milwaukee. If you're interested in these plates, Pogue's students will be doing a demo at the conference on them. If you can't make it up to Milwaukee, you can also check out his website for more information, and even catch a video on YouTube of one of the plates being printed.

I'll keep you all updated on my progress! Despite a few little hiccups, I still think these plates have a lot of potential, and I'm excited to use them in my own work soon.