Sunday, February 22, 2009

relief print part III

I've been working on creating a couple of additional blocks that will add colour elements into the new study with the stream and sand bar.
A few different relief surfaces are being implemented. A couple of the blocks are cut from pieces of battleship linoleum, two more are derived from carving out shapes from easy to cut vinyl and finally a couple more are from Scratchfoam (thin dense styrofoam sheet product) which I am affixing with spray adhesive on the underside to a thin pressboard base. The foam surface can be indented with instruments like ball point pen, pencil tip or end of a sharp wood stick. Ink is rolled on the raised flat surface with a brayer so indented areas do not retain ink and will appear as white or negative space on the paper. It can also have textures pressed into the surface and retain the impression to transfer onto the paper. When I create a block with this material I remove areas of unwanted foam by cutting away with xacto blade (pointed tip) and lifting off the baseboard with the aid of a pair of tweezers.

www.wetcanvas.com/forums/showthread.php?t=496056&highlight=scratchfoam

Images which involve the layering of colours from multiple block surfaces can present their own unique sets of problems. I have learned that registration is one of those challenges that a printmaker has to use their brain to figure out a good method for achieving a good end result.

A solution was shown to me by fellow wetcanvas member Printmakerguy who uses the ingenious method of a low level three hole punch that is attached to a plexiglass base. The paper is held in place by the three pins of this punch when the holes are punched out. I secure my blocks by making a brace created from cutting out an equal to block size hole in a piece of matboard, this is held in place with masking tape around the edges. You also want to allow for an extra inch of paper length at the top for the pin holes (this can be trimmed off after the last colour block has been printed.)
The whole works including the inked block and paper can pass under the raised top roller of a press to stop just short of where the pins are positioned (stop here so not to damage the roller). An even coverage of ink can be obtained with the constant pressure of the roller much more than hand burnishing with a baren.

Here is a step by step explanation of printing with my registration board system.
1 and 2. the basic set up for the block placement,  the block is inserted into the cut out depression in the matboard brace (equal size...tight fit). The block relief surface is slightly higher than the mat board surface.
2.
3. Paper is secured onto the three pins of the punch and the safety flap is lowered. The underside of the paper is where the ink from the surface of the block will transfer in reverse when pressure is applied on top of the pressure (in this case from a press roller).
3.
4. Another thin piece of cardboard is set on top of the paper and by turning the handles the bed of press carries the works underneath the roller. I stop short of the metal flange located at the head of the registration board so not to pass this portion under the roller and possibly damage both it and the three hole punch unit.
4.
 The cardboard piece on top is removed and the paper carefully lifted back to reveal the print.

Help for registering each block is achieved by first printing the key block (black) image using water soluble Speedball (acrylic) block printing ink onto one side of a transparent sheet of acetate or drafting film. (see fig. 1 & 2). Using masking tape I join a 2.5 cm (one inch) piece of heavy paper at the top to the acetate and punch the holes through this with the pins of the punch. The pins also act to secure the paper in the same position every time a different block is printed. Blocks are set it into the brace depression well and then the transparent key image overlay is placed over top to check if the block underneath registers in line with the image on the acetate.



fig. 1

fig. 2

I had an interesting challenge for the sky and water when I cut out a section of the easy to cut (a smooth surface vinyl type) material. The center of the block was totally cut back to a lower depth, so when the roller came across it during printing it would depress down into the hollow and cause wrinkling of the print paper. To overcome this problem I first cut away sections of vinyl from the block (located on the sides in the area where I do not want ink to print, then I ink the block and insert removable strips of fresh vinyl. These act as runners to allow the r0ller to span this lower area without dropping down into the depression during printing. (figs. 3 & 4)


fig. 3



fig. 4
To add the colour green to the print (which will appear through the small cuts in the foliage area and in the reflected treeline of the key block I have created a block using scratchfoam. I first lay a piece of drafting film over my black key image and mark off the corners of the block on the film. Since I can see through areas in pencil are marked where I want to have the green printed. Since this will be covered by black ink and the green will appear through the small cut marks I can establish these areas for the green as broad oval shapes. Then I lay the drawing on drafting film over a precut piece of matboard and line the corner marks on the film with the block corners visible underneath. I carefully insert a piece of carbon or graphite paper and applying firmer pressure with a pencil point re-trace over the pencil lines. I then trace the pencil marks on the drafting film onto the scratch foam (with carbon paper on top of the foam). I can then cut the traced shapes out of the foam sheet and spray adhesive on the underside. The pieces are then carefully set into place on the baseboard using the traced outline from the carbon paper on that surface as a guide. You will notice the ballpoint pen marks I have made into the surface, these act like a knife cut and will leave white areas on the paper just as a cut into a linoleum surface would (fig. 5).



fig. 5
In fig. 6 the blue was printed first and then the green block followed.
fig. 6
My next entry will focus on the continuation of adding more colours and the final key block printed in black to define the image.

2 comments:

  1. Great post as always. Figure 1 is amazing

    ReplyDelete
  2. nice system to understand the block printing system

    ReplyDelete