Goal

The goal of this exer­cise is to develop a sen­si­tiv­ity to process ink color choices avail­able for printing.

Objective

The objec­tive of this exer­cise is to cre­ate a reg­is­tered multi-color shirt. 

Background Reading

• Mac­Dougall, Chap­ter 6, p 67–83
• Mac­Dougall, Chap­ter 7, p 85–93
• Mac­Dougall, Chap­ter 9, p 103–113
• Mac­Dougall, Chap­ter 10, p 115–123

Safety Notice

• Do not look directly at the ultra­vi­o­let light
• Safety apparel required: gloves, safety glasses, ear plugs, respirator
• Safety Data Sheet (SDS) Index

Exercise

Each print will con­sist of four col­ors, with two col­ors printed by each stu­dent in the assigned pairs.

Part One

Pre­pare a screen for expo­sure. Using the pro­vided film pos­i­tives, expose, washout and dry a screen for the yel­low and magenta color, or half of the print.

A coated, exposed and dry screen is an essen­tial step to begin print­ing. With a screen prop­erly locked into the press, taped along the edges and reg­is­tered to the paper in the press, gather the nec­es­sary sup­plies for printing:

• Ink
• Squeegee
• Water spray bottle
• Paper tow­els
• Ink scraper
• Newsprint
• Paper

Ensure the following:

• Vac­uum is plugged in and switch is in the on position
• Foot switch works
• Mate­rials are close at hand
• Screen blocks are firmly clamped
• Off con­tact pen­nies are set
• Coun­ter­weight is fastened

Spray a light mist of water on the screen. Wipe evenly to dis­tribute the water. Emul­sion and screen fab­ric will absorb some water from the ink, caus­ing it to dry too fast. Pre-wet­ting will min­i­mize this risk.

Give the ink a quick stir to ensure ink it is mixed and con­sis­tent. Ink should have the con­sis­tency a lit­tle thicker than syrup. Add a quick spray of water and stir until correct.

With the screen raised and the squeegee rested at the top (hinge) edge, place a piece of newsprint on the press. Press the foot switch to arrest the paper. Lower the screen and grab the squeegee with both hands. Set the squeegee at a 45 degree angle above the print area and the ink, press firmly down, and draw the squeegee towards the body. Stop once past the image area (print stroke). Make a flood stoke to return the ink and squeegee to the top of the screen. Return the screen to the raised posi­tion and press the foot switch to release the paper. Remove paper and inspect. The ink should be a lit­tle wet and runny. Place prints on dry­ing rack. Repeat the process with newsprint until the print has crisp edges only where needed.

Once ready, place a sheet of final paper in the press. This time, pay care­ful atten­tion to the place­ment using the reg­is­tra­tion guides to ensure cor­rect align­ment. Repeat print sequence until complete.

Warn­ing: Do not allow ink to dry in the screen. Doing so will cause per­ma­nent dam­age to the screen.

Once print­ing is com­plete, scrape all remain­ing ink back to recep­tacle. Spray screen with a light mist of water and unlock from press.

Trans­port screen, squeegee and cards to washout boot. Gen­tly clean the ink from the screen and tools. Remove the tape and scrub with the brush to remove any adhe­sive residue. Check screen for clar­ity in back­light before cleanup. Turn off light and water once done.

Warn­ing: Do not allow emul­sion remover to dry in the screen. Doing so will cause per­ma­nent dam­age to the screen.

Part Two

Align­ing the sec­ond and sub­se­quent col­ors to the first is essen­tial to main­tain­ing print pro­fi­ciency. Place the film pos­i­tive and/or paper securely aligned to the reg­is­tra­tion guides and acti­vate the press vac­uum. Place the screen close to reg­is­tra­tion as pos­si­ble and tighten the lock­downs on the hinges. Try to adjust the reg­is­tra­tion through wing nuts on rear of press. The reg­is­tra­tion guides on each color should match. Press down the screen and make sure the emul­sion and screen col­ors do not inter­fere with the process. Care­fully align screen to pos­i­tive or first color. If the screen does not align, reset the reg­is­tra­tion screws in the rear and the place new guides on the press. Once reg­is­tra­tion is con­firmed, pro­ceed to print­ing the  sec­ond (sub­se­quent) colors.

Often the color reg­is­tra­tion can change over time. Slight adjust­ments to the sys­tem can be made, but it is likely the vari­a­tion in print­ing is to blame. It is bet­ter to look for trend over more than one print than just assume inconsistencies.

If col­ors mis­reg­is­ter, please con­sider the cause as a trou­bleshoot­ing exercise:

• Paper: humid­ity can cause the paper to swell and shrink sev­eral points. Rack paper (place on dry­ing rack) 24 hours before print­ing to acclimate.
• Poor first color print­ing: sloppy paper place­ment, poor stop­block place­ment, loose hinges or reg­is­tra­tion guides.
• Poor sec­ond color: Poor tech­nique, squeegee angle, poor paper placement.

Part Three

Once print­ing and cleanup is com­pleted, label each print by printer, print num­ber, print date, color name and ink man­u­fac­turer in the spaces pro­vided on the print.

Part Four

Repeat Parts One, Two and Three for the cyan and black col­ors to com­plete the print. Switch order of peo­ple so each stu­dent has the oppor­tu­nity to expe­ri­ence the print order.

Technical Specifications

• 5 x 7 in. (land­scape) art­work area cen­tered on an 9 x 12 in. sheet of paper.
• Four color

• The fol­low­ing rubric posted on D2L will deter­mine exer­cise score: Exer­cise Grading

Techniques

Brain­storm­ing, con­cep­tual devel­op­ment, draw­ing, dig­i­tal image devel­op­ment, emul­sion coat­ing, expo­sure, washout, reg­is­tra­tion, print­ing, cleanup, reclamation.

Supplies

Art­work, com­puter, appro­pri­ate soft­ware, film pos­i­tives, screen, emul­sion, expo­sure unit, washout booth, print­ing press, squeegee, paper, emul­sion remover, scrub brush.

Deadlines

Monday/Wednesday, March ⁶⁄₈, 2017. Exer­cise Given.

Monday/Wednesday, March ²⁰⁄₂₂, 2017. Observed by instruc­tor as part of group demonstration.