The Pitch - Screen-printing

The Pitch – Screen–Printing

Screen-printing is an adaptable and resourceful printing process; it can cover over media including paper, plastic, glass, metals, nylon, and cotton. The main advantage that screen-printing have over any other printing processes is that the press can print on substrates of any shape, thickness and size. There is a wider range of inks and dyes that are available to use due to production rates improving. This has been a result of the development of the automated and rotary screen-printing press, improved dryers, and U.V. curable ink.

Many factors such as composition, size and form, angle, pressure, and speed of the blade (squeegee) determine the quality of the impression made by the blade; the machine can produce as many as 25,000 responses without significant degradation of the image. Meaning label t-shirts to posters and flyers artwork can be made.

There has been an improved drying system, which has significantly improves production rates; there have also been development and improvements of U.V and curable ink technologies. Development has been made in the rotary screen press, which allows continuous operation of the press this is one of the more recent technology developments.

Technique

When you are going to do a screen print, you have to put your design on either draft paper or acetate. You can either draw straight on the paper or you can print it out on the paper, but need to be aware if you use acetate while printing the heat can shrink the acetate. For the screen print to work you must work in black, so if you are printing images out make sure they are grey scaled and maybe half toned or posterize, editing the contrast could also help.  There is a few different media you can use when drawing your design straight on, you can use ink, pen’s that contain ink pigment.

When you get a screen, you should wash it with hot water, as this will get off any chemicals off that may still be there off pervious users, so after may be a good idea to use a jet wash too to make sure everything’s off and it’s totally clean, you should do both sides.  To dry it, put it in the dryer and they have big fans that dry the screens, make sure you turn it off before opening the doors as you may risk breaking the dryer, once you place your screen in it should take up to 10 – 15 minutes to dry.

Once dry, you can now cover the screen with the motion, to do this you have to place the emulsion in a tray, and evenly apply pressure when dragging the try up the screen, it’s best to do two coats on each side, but run the tray up without tilting the emulsion on to scrap off any excess left on. When done, it goes in another heater so the emulsion hardens, it should be left in for 20-30 minutes, no longer than half an hour though.

Keeping the screen in the screen-printing room, so it doesn’t get exposed to too much light and ruin the print/s. Place the paper with your design work you created earlier face down so ink side is touching the screen. Then place in the light machine, so the screen can be exposed, it uses a UV light to fully exposes the image, whatever is black will print and what is not will not sure up.

 Once exposed you can take off you designs, and start to wash off all the excess emulsion, so only your design will show. You should wash the screen with hot water to soften the emulsion. Then jet wash the screen so it is all clean and washed off and only your design is left. After all washed should put it in the dryer again for 10-15 minutes.

When the screen is dried, you may want to pin it, you can look at the screen on a light box, and see if the are any parts that have exposed that you didn’t want there, so you will paint the emulsion on any bits you want rid off, but make sure when painting the bucket containing the emulsion is on as much as possible as the light will affect the effects. After you pin your screen you will have to dry it and re-expose your screen so the emulsion is hardened.

You should put tape around the edge of your screen before you make any prints, you need to mix and make the ink pigment, once made you can start making your prints. Place your screen down, place, and inch of the ink pigment at the top of the screen. Get an squidgy and with an evenly amount of pressure pull down the ink. Make sure you scrap off any excess off the screen.

You should wash your screen regularly as the ink will dry and block up so you won’t be able to produce more prints with the screen, after the screens washed make sure it is dry before trying to produce more inks with it.

Once finished with the ink and creating designs, you have to wash the screen to its original state so your design won’t longer be on or may be ever so faintly, this is to be efficient and so things can be reused. This might not be the case industry but more so in small organization or educational purposes.