Category:Screenprinting

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Screenprinting



General Info
Shop Colors[[File:|100px]]
Shop RulesMissing
Managed ByJade Harley
HoursSame as membership hours
Operational Status of Tools
Tool Maintenence Tickets



Contents

About the Print Shop

The print shop provides tools and space for screenprinting. It is set up primarily to print on paper and fabric, but can accommodate printing on various other materials with preparation.

The print shop is located next to the multipurpose room.


Reserving the Print Shop

If you are planning to come in and print, it is recommended that you schedule blocks of time using the reservation system [help]. The print shop can accommodate 2-3 people printing at the same time. Please check the print shop calendar before beginning a print project to ensure that the space can accommodate you.

If there is a class scheduled the print shop is not available for anyone else to print until after the class is over, as the class requires full use of the space.

Take note that we only have two each of paper and shirt printing stations, so the 2-3 people printing will have to be some combination of these.


Please reserve only the time you need, and label your reservation as follows: FIRSTNAME-Material

An example would be:

  • JOHN-Fabric

or

  • NANCY-Paper


This is to help identify what area of the print shop you will be working in so others can evaluate whether they can also work in the space without interfering with your project.


Equipment

  • 4 Color / 1 Station Press
  • 1 Color / 1 Station Press
  • (x2) Paper Printing Stations (hinge clamps)
  • Flash Dryer - 1500 Watt
  • Heat Press
  • Exposure Lamp - 250 Watt (Metal Halide bulb)
  • Dedicated Sink
  • Washout Booth (with backlight)
  • Power Washer
  • Squeegees (various size / durometer)
  • Scoop Coats (various size)
  • HP Deskjet 9800 Inkjet Printer (13” x 19” max print size)


There are also spaces to store screens:

  • While the emulsion is drying (light safe)
  • To dry after washing in sink
  • For use at a later date (please use tape to label with your name / email)

Coming Soon:

  • Flatbed Scanner - 11” x 17”
  • Dedicated Computer with Adobe software
  • Etching Press

Materials

Squeegees

These come in a variety of widths and hardnesses for different applications. They are usually color coded as:

Red – Soft

Yellow – Medium

Green – Hard

The thickness of your ink, and the mesh count of your screen can impact your choice of squeegee, but for most T-shirt or paper printing applications a Medium squeegee is the best bet.

Scoop Coaters

These are used to transfer emulsion to your screen. They also come in various widths to match the size of your artwork or screen.

You should always fill the scoop coater at least half way, even when coating a single screen, to make sure it flows fast and can evenly coat your screen. Excess emulsion can be returned to the emulsion container when done.

Make sure to close the emulsion container between uses, as this helps prevent unwanted exposure and evaporation

Screens (Mesh)

Mesh Count is determined by the number of threads per square inch. The higher the number, the greater the detail.

A 160 mesh, has twice as many openings between the threads as an 80 mesh, and they are half the size. It is similar in concept to pixelation. Low mesh numbers have fewer and larger openings, and higher mesh numbers have more tiny openings.

Ink (Acrylic / Fabric)

The shop is set up to work with water-base inks. Speedball inks are most common, but you are welcome to use other water-base inks.

Acrylic ink is used for paper, wood, cardboard.

Fabric ink is primarily used for T-Shirts, canvas, etc., but can also be used for wood and paper, however, it takes longer to dry on those applications than acrylic ink does.

Strip-e-doo

This is a reclaimer / degreaser combo agent. It is used to clean the emulsion off a screen and prepare it to be used again for a new design.

Classes

Single-Color Screen Printing: One Day Introduction

This one day workshop is 5 hours long and runs on Saturdays usually once or twice a month. It covers everything you need to know to begin printing on your own. This includes art preparation, screen selection, emulsion and exposure, registration, ink selection and printing techniques. Students will print their own designs in class on the material of their choice. PreReq: None

4-Color Process Printing

Coming soon.

Print Your Own Greeting Cards

Coming soon.


Private lessons and corporate group events are available and led by Erik Heumiller. Contact at erik.heumiller@gmail.com.

Art Preparation

Coming Soon!


Coating Screens

There are a couple different coating methods.

1:1

  • Step 1 – Coat the bottom side of the screen.
  • Step 2 – Flip and coat the top (or inside) of the screen.

2:1

  • Step 1 – Coat the bottom side of the screen.
  • Step 2 – Flip and coat the top (or inside) of the screen.
  • Step 3 – Coat the bottom side of the screen again.

2:2

  • Step 1 – Coat the bottom side of the screen.
  • Step 2 – Flip and coat the top (or inside) of the screen.
  • Step 3 – Flip back to the bottom side of the screen and coat a second time.
  • Step 4 – Flip again and coat the top (or inside) of the screen a second time as well.

The more coats of emulsion on a screen, the longer it will take to expose, as the UV light needs to penetrate deeper into the emulsion to harden it.

The end result you’re looking for is an even coat that is glossy on both sides.

Look for dust, fibers, etc. that might be problematic when exposing you’re screen.

Store flat side down (bottom) in the horizontal rack to dry. Storage at this stage should be light proof to prevent premature exposure of the screen.

While the screen is drying, the moisture is allowed to evaporate out of the emulsion, leaving a dry film on the screen. The timing will depend on humidity, air circulation and number of screens in the box, but 1 hour is a safe starting point.


Screen Exposure (Photo Emulsion)

The Print Shop at Artisan’s Asylum is set up to work with water-based print workflows.

The preferred emulsion to use in the shop is Ulano TZ (a water-based, diazo photo emulsion). The processes and timing detailed on this page are specific to this material.

The exposure lamp we use has a 250 Watt Metal-Halide bulb.

Based on a 1:1 coating method, using Ulano TZ emulsion, this lamp will expose a screen in 7.5 minutes.

Use of a 21-Step Stouffer Scale during screen exposure is recommended. This can help diagnose any issues that may arise.

Process:

  • Step 1 – Place the screen bottom side up to the lamp, with properly sized black felt blocker beneath it. This should fit within the aluminum frame and prevents reflected light from hardening the inside of the screen.
  • Step 2 – Reverse the artwork transparency so it is backwards, and place on top of the screen. Try to aim for the middle or just above middle of the screen. Make sure the artwork is not rotated at an angle.
  • Step 3 – Place correct size glass on top of transparency. The glass should sit inside the frame of the screen and acts to hold the transparency flat during exposure.

NOTE – the glass can sometimes refract light along the edges that leads to a line of un-hardened emulsion. This is usually not a problem and simply requires you to tape over it.

  • Step 4 – Start the timer. Should be set for 7 minutes and 30 seconds.

Once the timer goes off, remove glass and put away safely, then remove transparency and set aside. Take the screen immediately to the washout sink.

Using the Stouffer Scale When you develop the stencil, areas that didn’t get enough exposure to survive development will dissolve with water and rinse down the drain. You want a minimum of a Solid Step 7 that survives and holds in the mesh. More exposure will make your stencil more durable and less will make the stencil less durable.

The guide numbers are clear on the film so they get 100% exposure. You will know you have a Solid Step, because you won’t see a difference between the guide number, (7), and the patch of stencil around it. If you have a ‘crusty’ step, you know that unexposed stencil on the inside of the screen has broken down and washed away with water.

You can use math to calculate an exposure correction because the amount of each step is a known amout. Each step to increase or decrease exposure has a value of 1.414. If you need to adjust more than one step, you have to multiply the steps.

1 step is 1.414 exposure 2 steps 1.414 * 1.414 = 1.9999 so you should double exposure. 3 steps 1.414 * 1.414 * 1.414 = 2.827 means about 3x exposure. 4 steps 1.414 * 1.414 * 1.414 * 1.414 = 3.99758 which means 4X.


Washout

During washout, the areas of the screen that were protected by the black areas of your transparency are able to re-absorb moisture.

This allows those areas to soften and wash away, leaving you with a stencil of your image, suspended across the mesh of the screen.

Start by placing your screen in the washout sink, with the bottom of the screen facing you.

  • Step 1 – Using the garden hose sprayer, set to the “Soaker” on the dial, drip water gently across both sides of the screen.

I usually soak the front and back for 5-10 seconds each, and then wait 30 seconds and repeat. I do this 3 or 4 times and that allows the emulsion to re-absorb the water nicely.

  • Step 2 – Turn on the washout booth light using the foot petal and change the setting on the garden sprayer to “Flat”. Then begin spraying the bottom side of the screen from about 12-inches away. Moving back and forth across the entire design.

The softened emulsion will begin to break away and you can use the light to see what areas still require washing.

NOTE – Try not to get too close to the screen or linger too long in any one position. This can deteriorate or damage parts of your design if there are tiny detailed elements to it. Just use your judgement.


Registration

Registration differs slightly between tabletop printing and the 4-color shirt press.

Tabletop Printing

  • 1) Start by locking the screen into two of the hinge clamps. The hinge clamps have a built in 1/8″ pad on the bottom to help you set the off-contact.
  • 2) Once the screen is in the clamps, I’ve found the easiest way to register the placement of the art is to lift it up, and using two small pieces of tape, place the transparency on the bottom side of the screen so it matches up. Then I place another larger piece of tape, facing out, on the transparency.
  • 3) Then when you lower the screen down you can apply pressure and that outward facing tape ends up taping the transparency to the table, creating a hinge of sorts.
  • 5) This shows you exactly where on the table your artwork will print, and allows you to align your paper or other flat materials, directly under the art.
  • 6) Once you have figured out the positioning you can use plastic cards or tape or any other suitable materials for creating a jig to allow for fast and easy alignment.
  • 7) Now you’re ready to fold the transparency out of the way (using the tape hinge) and you can begin printing.

4-Color Station

  • 1) Load your screen into the clamps of the press.
  • 2) Then align your transparency on the platen. If you are printing in the center of the shirt, make sure your artwork is centered on the platen. Tape the transparency down, when it is in place.
  • 3) Lower the screen down to begin registration. You will need to loosen the thumb screw on the underside of the platen to allow it to slide in / out and match up with the image on your screen.
  • 4) Once you have the distance set, tighten the thumb screw on the platen to lock that in place. Then loosen the clamp holding the screen and finalize the placement of the artwork to match up.
  • 5) Once the artwork and screen are aligned, place a hand on the image of the screen to hold it in place, then alternate tightening of each handle to prevent and shifty while you lock the screen in place.
  • 6) Now you can remove the transparency and begin printing.

NOTE: You want as much of the aluminum bars of the screen frame to be under the pressure of the clamps (on the press) as possible. That helps to keep the screen rigid and prevent it from shifting during use.

For both of these methods, it is easiest to use the corner registration marks to aid in alignment. If you can align to registration marks (opposite corners) then everything between them is aligned.


Print Technique

There are two ways to go about printing.

  • Pulling the squeegee toward yourself.
  • Pushing the squeegee away from yourself.

In either method, the goal is to have the squeegee angled in a way that only a single edge of it is in contact with the screen.


Cleanup

Since we are working with water-based materials, warm water is all that is needed to clean any remaining ink out of the screen.

If you wish to use the screen again, simply wash out the ink and let the screen dry before the next use.

If you wish to reclaim the screen to use with a different design, the process is as follows.

  • 1) Wash out any remaining ink.
  • 2) Make sure the screen is wet.
  • 3) Use the Strip-e-doo to remove the emulsion. This is a two-in-one cleaning agent. It is non-toxic and acts as a reclaimer and degreaser all in one.

The reclaimer strips off the emulsion, and the degreaser cleans the screen so it is ready to be used again and ensures that there are no elements on the screen that will prevent the next coating of emulsion from properly adhering to the screen.

  • 4) Wet the scrub brush atop the washout sink. Apply a couple tablespoons of Strip-e-doo to the scrub brush and immediate apply to one side of the screen. Make sure to move back and forth, covering the entire screen. Scrub the whole side until it starts to become slightly sudsy.
  • 5) Flip the screen and repeat step 4 on the other side of the screen. You will notice that the emulsion has started to dissolve from the screen. You can assist this by scrubbing both sides of the screen until there are no details remaining and the screen looks free of solid emulsion.
  • 6) At this point, you can follow the instructions on the power washer to spray out the screen. Make sure to thoroughly wash the screen with warm water, leaving no trace of Strip-e-doo behind.
  • 7) Then set aside to dry before using again.

Make sure to clean up any other areas of the shop before you leave.


Pages in category "Screenprinting"

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