I have an old National manual screen printing press, It has 6 colors but I am having trouble learning to print manually to get a sharp crisp image, especially with white. My white looks fuzzy around the edges. How can I screen print white manually and get a sharp image, especially on dark sweatshirts and T shirts. I have a fairly new squeegie that seems to be pretty stiff. Thanks Kim
Are you pulling the ink in only one direction? I watched a how to video before I started and they told me to pull then push the ink. It doesn't work very well. Also, make sure all of your registration nuts and bolt are tight. I have a cheap press, and sometimes the bolts get a little loose and the screen will shift a little causing a haze. One more thing, make sure you have good off contact. There needs to be a little gap between the garment and the screen.
To properly setup a job using white ink you first must
understand a little bit on how to select the proper mesh size. Because white is
thicker, you want to print through the lowest proper mesh size that applies to
that print. If you try and print white through a higher mesh screen which has
much smaller holes in it (SEE MORE INFO on Silk Screening Mesh Sizes) its going to make it much harder to push the ink through the screen. It’s also not going to allow as much ink through the screen as a lower mesh would.
Typically you want to print white through mesh sizes ranging from 110-156. Granted sometimes the image dictates a high mesh count. For instance, since a half tone or fine line drawing cannot hold on a lower mesh screen, you’ll have to use a high mesh frame and apply more passes to achieve a bright white. For the most part however, you’ll want to use the lower meshes so that a larger amount of ink is deposited on the shirt.
The second part of setup is to insure the screen is adjusted properly on the press. You want to be sure that you have a proper off contact of about 1/8-1/16 of an inch. Since white is a little thicker, you may want to go with a slightly higher off contact than normal, perhaps around 1/8 of an inch. Off contact is the height between the screen mesh and the substrate you are printing on.
Proper off contact also allows the ink to be cleared from the screen mesh easily by releasing the mesh upward directly after the print stroke leaving all the ink smoothly on the shirt. One thing that you also want to be sure to apply when printing white ink is an off contact tab. This is a small piece of material (ie. a penny, cardboard, paper, a piece of plastic) that is the height of your off contact. This tab is placed on the end of the screen frame where it hits the top of the neck platen and not the shirt. By using an off contact tab, you insure that your off contact will remain through the entire print stroke.
The tab keeps the end of the screen up although you are pushing down on the mesh during the stroke. Without an off contact tab, you may find that you have a harder time clearing the mesh because the screen wants to stay flat against the shirt with ink stuck in it.
If you don’t have the proper off contact a few problems could arise. If your off contact is too low then you will not be able to clear the screen properly. You should see the screen mesh bounce off the shirt and be able to see the ink and the shirt through a cleared screen mesh. If your ink stays in the screen mesh and the screen mesh sticks to the shirt, when you pull the screen up your ink will look very rough and parts may pull back off the shirt. If you’re having this problem you may need to raise the off contact a little bit. Also, this problem could arise from your actual print stroke which will be discussed later.
On the other end of the spectrum, if you’re off contact is too high; you’ll have to push down extremely hard on the squeegee in order to get all the ink down onto the shirt. I’ve been out to shops to help customers who literally had almost a half of inch of off contact. If your off contact is too high, not only will it be hard to transfer the ink onto the shirt, but there’s a good chance that your screen won’t come down in the same spot every time. This could cause a blurry image or double images after a flashing. A proper off contact is extremely important for a good looking image and an easy print. Many new printers stand back from the press, you actually need to stand over the press to focus your pressure down and not back. When your pressure is focused down, then you simply move the squeegee back over the print. With the proper squeegee angle, all of the ink will properly shear through the image and over your screen. In fact you should be able to run your finger over the design after its printed and barely any ink should show up on your finger.
Now let’s talk about the speed of your print. When we instruct printers to use the proper squeegee angle and pressure, the first impulse they have is to move the squeegee about the speed of a turtle. If your speed is too slow you won’t be able to properly release and clear the screen. After a print stoke, many beginners tend to sit back and look at their print, then slowly pull up on the squeegee not allowing the screen mesh to bounce back up leaving ink still stuck in the screen. After a faster stroke, you need to almost give the screen a little pop in order to get the mesh to bounce back up leave a smooth crisp print on your shirt. This is achieved by a simple flick of the wrist, the same flick you would make to insure that you pick up all the ink on your squeegee blade. Only to create this pop and release the screen, the flick must be done a little faster.
Finally, when flashing in between passes, you must wait until the shirt cools down a little until you print again. This is much easier to achieve on a multiple station press because it allows the pallets to cool down. On a single station press you may have to wait a few moments and wave your hand across the pallet to cool it down.
Help with Manual printing 
