As our screens are re-usable, we just need to get that old stencil off, so we can start afresh with a new design. Here’s how we do it: (Wear gloves)

1. Stripping

You need a stripper or screen wash that will remove your particular type of emulsion. Most strippers are cross-platform, but some emulsions need a specific product. I use what is referred to as Gel Strip, a blue paste that you apply to the emulsion. There are also powders that dissolve in water that do the same thing. 

I use a normal nail brush to apply the stripper. I use this to spread the product around the screen evenly and the scrubbing action works the gel into the emulsion. I do not scrub very hard. Once I have applied the stripper to both sides of the screen, I can see that it is starting to work the emulsion back to a water soluble state. There is pink residue on my scrubbing brush already from the emulsion starting to come off. 

At this point I use a bit of water on the brush to work it even more, scrubbing both sides of the screen gently. After a minute or so, the emulsion should be ready to come off with water. I use a spray hose or some use a high pressure hose. It should come away quite easily. Rinse thoroughly, make sure you spray out all of the emulsion particularly on the sides of the screen as any bits left behind could hinder the coating process later. 

You may notice that the mesh is not clean at this point. If you can hold it up to the light and see through the mesh, even if it appears stained with ink form the previous use then you can skip the second step and go to degreasing. If the ink residue appears to be a physical obstruction (usually caused by a super-cover/opaque ink), this can effect your next exposure and you should go to step 2. 

2. De-hazing

For this process I use a ghost image/haze remover. Gloves are a must and a mask or protective glasses are a good idea. Dried ink remaining in the mesh is referred to as haze. Haze remover is a caustic gel that separates the ink from the mesh and allows it to be washed away. I only use this step when I have to due to the harshness of the chemical.

Again using a nail brush, I apply the gel only to the stained areas - it is not necessary to spread it all around the screen. I scrub gently front and back of the mesh and then leave for about five minutes. The ink should wash away easily. Again, rinse thoroughly. Sometimes the darker inks may not wash out fully, however if you can see through it, it’s fine. Go to step 3.

3.Degreasing

This is the final step. Degreasing removes impurities from the mesh, such as chemical residue. If your screen is not clear of residue, the emulsion can repel from the mesh when you try to recoat.

Basically all it is is a detergent, so I dilute some dish liquid in a spray bottle and spray it onto the screen. Again with a nail brush I scrub it into the mesh, spreading it evenly on both sides until I get a bit of lather going. Rinse very thoroughly, especially around the frame, so that no drips transfer onto the mesh while drying.

That’s about it. You should dry it in your screen cupboard or somewhere it won’t be exposed to dust or dirt. Make sure it is fully dry before you re-coat.

Anything that holds out light will work as a film positive.

If you understand this basic premise, you can make just about anything into a film positive. Here are some methods you can use :

Laser printed transparencies allow you to create a cheap film positive from a computer file or scan. You can buy blank transparencies, suitable for laser printers, at stationery stores. The one drawback is that laser printers use toner, and the density of the image may not be good enough to effectively hold out light for a decent exposure. There is a product called Toner Density Spray that you can apply to your transparency after it has been printed and that will darken the toner and make it more reliable as a film positive.

A photocopier is another good alternative for creating cheap filmwork. Use blank transparencies to photocopy your image onto the film. Again, the use of toner density spray may be necessary. Another thing you can do to make your positive more opaque is to photocopy two transparencies and lay them over each other. Perfect alignment is difficult to achieve with this method, as photocopiers, as well as laser printers, use heat to create the image. There will always be a degree of shrinkage in your transparencies, but this method can work well enough.

Tracing paper also works a treat as a film positive. It is clear enough to let through the ultraviolet light, so if you ensure that your design is dark enough to hold out the light, then this is a good method. You can use this if you do not have a computer, or would like to retain a hand drawn feel to your design. Opaque pens are great, usually they are available from art stores in different tip thicknesses and such. You can use these to draw/trace your image onto the paper. Opaque pens contain a red ink, and under UV light, red is as powerful as black.

Anyway, this is just the tip of the iceberg. When you think about the statement above, you may want to experiment with everyday items that are opaque enough to hold out UV light. Mesh bags like those you buy oranges in can create a nice effect. Pieces of paper, masking tape, leaves, etc, can all be used to make some sort of image. As long as light cannot fuly pass through it, you will get some sort of effect.

Check out the details and go along to support our newest crop of artists and designers. Or take a good look at the site if you can’t make it. There is some really nice work to see.

Click on the button to visit the Movember site.

Jake from Fuzion Body Boarding - Awesome new WA based surf label. Get on board. -myspace.com/fuzionbb

Cindy from The Beat Collective - Not for profit DJ Network available for parties and the like. -thebeatcollective.com

Film Output

We have the capability to produce high quality film positives from computer files.

If you only have a hard copy, we can scan your artwork and output it to a printable file. An artwork charge will apply if your image needs to be traced or modified for printing.

• A3 Film Positive - $25.00
• A4 Film Positive - $15.00

Screen Cleaning

Get your screens stripped by us! We can strip your old stencil, then de-haze and degrease your screen to get it ready for re-coating.

• $20.00 for one screen
• $15.00 for each additional screen

Screen Coating and Exposure

So, you don’t have the facilities to coat and expose a stencil! Don’t fret. We can do that too. Provide your own film positive or get one from us.

• $25.00 for one screen
• $20.00 for each additional screen

First off, it is important to start with a clean screen. Even if you are using a new screen, you should degrease the mesh before coating.

There are commercial degreasers available from screen suppliers, but a simple solution of washing detergent and water will do the job. Just fill up an empty spray bottle.

DEGREASING

Spray the solution onto the screen, then use a clean scrubbing brush (not a heavy duty brush, just a nail brush with bristles that aren’t too coarse) to push the solution around the screen. You should work up a bit of a lather like this. Scrub both sides of the mesh. This process is intended to get rid of any impurities and/or residue from other products or anything that could repel the emulsion and stop it from adhering to the mesh. The entire screen should be thoroughly rinsed out and dried.

The use of the scrubbing brush also helps prepare the mesh to take the emulsion, giving it a slightly rougher surface for the coating to hold onto.

When your screen is drying, both after degreasing and coating it needs to be protected from any dust or dirt, and after coating, it is imperative that it be protected from light, as the emulsion is light sensitive and premature exposure will render your screen useless. A box big enough to house the screen is ideal. Most screen printers have drying cupboards with racks so the screens can be dried horizontally for an even coating.

When your screen has been degreased and dried, it is ready to be coated. For this we use a scoop coater, or screen applicator.

COATING WITH PHOTOGRAPHIC EMULSION

1. Be sure to give your emulsion a good gentle stir before pouring it into your applicator. Make sue your applicator is clean. Carefully pour some emulsion into the applicator. Make sure you do this and the following steps in subdued lighting.

2. Place your screen vertically on a sturdy bench. Hold it at the top so that it can be tilted back and forth while you are coating. (If you are right handed, hold the screen with your left hand and vice versa for lefties.) Hold the applicator to the bottom of the mesh, manouvre it so the emulsion lines up evenly across the width of the screen.

3. Tilt the applicator up so the emulsion makes contact with the mesh. Draw the applicator slowly up the screen, while maintaining strong contact with the mesh. When you reach the top of the mesh, stop. Tilt the applicator down to allow excess emulsion to run back into the applicator, then scrape up as you pull away so it doesn’t drip.

4. Turn the screen around and repeat the step. When you coat the other side, excess emulsion will be pushed back through the mesh to the opposite side. Every screen printer has different ways of doing things. Some will leave it at that, some will scrape one or both sides of the screen to remove the excess. Some will only coat one side. It is a matter of experimenting with what works best for you.

If you make a mistake, just scrape both sides and start again. When you are done, retain any excess emulsion for future use.

This is a good demo video.

http://youtube.com/watch?v=FxIuiff1TNs

Polyester monofilament is widely used throughout the screen printing industry, but there are a range of mesh fabrics available including stainless steel for printing on things like glass, ceramics and even circuit boards.

We use 43T mesh. The “43” refers to 43 threads per linear centimetre, while the “T” refers to the thickness of the thread. T = normal.

Visit these sites for information on screen mesh grades.

http://www.gabbasps.com.au/prods/mesh.html

http://www.escreenfilter.com/screensolution.htm#recommendationstoselect
good diagrams here of mesh up close

More to come.

Screen printing is an exciting and versatile art form, which allows the printer to create an image, and then reproduce it over and over again. If you have ever done stencil art, the concept is the same. Paint, or in printing, ink, is forced through the open areas of the stencil onto the surface below.

The following steps outline the screen printing process.

1. SCREENS, MESH AND COATING

For t-shirt printing, we start out with a wooden or aluminium framed screen. The frame has mesh stretched across it, similar to a painter’s canvas. The mesh that t-shirt printers commonly use, is known as 43T and is made of a polyester monofilament. For more information on screen mesh grades and uses, click here.

The mesh is coated on both sides with photographic emulsion. This is a light sensitive substance of glue-like consistency, which is drawn evenly up the screen so that the mesh is covered by a thin coating. To get an even, controlled coating, screen printers use a scoop coater, (sometimes known as a screen coater or applicator) which is made of aluminium and holds the emulsion ready to coat. For an explanation of the coating procedure, please click here.

The coated screen has to dry in a dark, dust free area. It is also advisable to dry the screen in a horizontal position, so that the liquid does not run down the screen and dry unevenly.

2. FILM POSITIVES AND REGISTRATION

Meanwhile, a film positive should be generated from the artwork being used. A film positive is essentially a black or opaque rendering of an image on a clear film. For more details on the principles of film positives and the various methods used to create them, click here. (page coming soon)

The film positive is then positioned on the baseboard or printing area and marked with registration points. The dry screen can then be registered to the printing area and the registration points transferred to the screen. The film positive can then be taped to the screen in the exact desired position. The film positive is placed so that right reading is possible from the inside of the screen.

3. SCREEN EXPOSURE AND WASHOUT

With the film taped to the screen, it is now ready for exposure. Photographic emulsion reacts to UV light by hardening, so the opaque areas of the film positive act as a block out, protecting the emulsion underneath from hardening. After adequate exposure time, the screen is rinsed, and those areas left unexposed to the light remain water-soluble while the rest of the screen has hardened and cannot be washed away. The emulsion in the unexposed area softens quickly and rinses out of the screen revealing a stencil of the image.

The screen is then allowed to dry before being checked and taped up ready for printing.

4. THE SET-UP

Next, the film positive is returned to its position on the baseboard, and the screen is placed in the head of the carousel. To learn more about the role of the carousel, please click here. (page coming soon)

The screen is then lowered over the film positive, manouvred into position directly over the design and locked into the carousel head. The design position should be marked on the baseboard in some way to indicate where the print will fall. This aids in the repeated positioning of t-shirts or items to be printed. The film positive is then removed, and an appropriate squeegee selected. (The squeegee should be wider than the design you intend to print so that the ink is distributed evenly across the fabric.

A squeegee is what printers use to force ink through the open areas of the mesh. They come with a wooden or aluminium handle holding a thick strip of rubber. The rubber is available in various grades of thickness and flexibility.

Next comes time to select an ink. At Strumalum we use water based inks which have their own advantages and disadvantages. For more information on inks, please click here. (page coming soon)

5. PRINTING

A test print is always advisable before the real deal. The printing area is prepared with a light covering of spray glue, this will ensure that the fabric doesn’t move while printing, especially important if a second coat is required or if there are multiple colours to be printed. The screen is then lowered into position, ink is laid on the screen below the start of the design, and the squeegee is used to draw the ink over the open areas of the stencil.

A Note on Squeegee Use

Squeegee angle and pressure is important while printing. If the squeegee is held at an angle that is too low, too much ink can go through the screen causing a bleed onto the fabric. If this squeegee is held too upright, the opposite problem can result. It is generally considered best to have the squeegee at an angle of 60 – 70 degrees. See picture. This is the most comfortable way to print and maintain even pressure as well. A good print does not require the squeegee pressure to be overly forceful, just firm enough to make good contact with the baseboard and be able to push the ink through the mesh cleanly, a second or third pass can be required to clear the screen. For more tips on squeegees, and troubleshooting during printing, click here. (page coming soon)

A Note on Flood Coats

With water based inks, any time the screen is not in use, the ink is in danger of drying in the screen, which can cause blockages affecting the print. This is where a flood coat comes in handy. This takes some practice to get right, but the general idea of it is to cover the open areas of the screen with a layer of ink to protect it from drying out too quickly. For more info on the flood coat, click here. (page coming soon)

After a print, the ink needs to be dried before a second coat or another colour can be added. A flash cure unit can be used to dry the print. We have a fan forced unit that uses ceramic elements to heat the area. This method takes about 10 – 20 seconds to dry.

When the print is completed, the item is removed from the baseboard and the next item to be printed is put down.

6. CLEAN-UP

When the print run is finished, it is important for water based users to clean the screen immediately so that no ink dries in the screen and hinders future use. Screens, squeegees and spatulas wash up with water. Care should be taken to ensure the screen is cleared of all ink, front and back. Squeegees should also be inspected for ink lurking in the crevices near the handle.

7. HEAT CURING

Before printed fabric can be ready for use, it must be heat cured. For water based inks, the curing process draws water out of the ink leaving only the pigment to bond to the fabric. This is achieved by applying heat usually by running the garment through a tunnel dryer which is like a pizza oven. Other methods are discussed here.(page coming soon) Water based inks generally cure at around 180 degrees celcius for about 3 minutes. , (different inks have different curing times and temperatures)

When it’s all done, the stencil can be stripped from the screen and re-used for the next design. Also, by retaining your film positive (and keeping it in good condition), you can always re-expose the stencil for a re-print anytime in the future. For a rundown of the screen reclamation process, click here. (page coming soon)