It appears that some of the widespread problems new display screen printers run into is printing white ink. I've heard plenty of questions like: Why do all my other colors print fine and white is so robust? Why is it that my white ink is so thick? Why can't I get a easy white ink? It's at all times rough and appears to have texture to it. Is there anything I can do to skinny my white ink to make it simpler to print? Also feedback like: "Our white ink is bad, it comes off after solely a couple of washes." "
There's one thing improper with my press, it prints positive when I'm printing on white shirts, but after I print on dark shirts the white ink could be very blurry."
Sadly, the solutions to these quarries often lie in the printer themselves. No, your white ink is not defecting, your press probably works high-quality, and also you should not must skinny the ink. Sure, you probably want to vary some variables and strategies during the printing process. The truth of the mater is, the reply is in the question all along.
So why does the display screen printing course of work fantastic for a while after which as quickly as you begin printing white ink, smash, a street block. The truth is, you may have been doing the mistaken issues the whole time, it simply didn't present up yet . It is like swimming, certain you can dog paddle and flounder around the pool all day. Nevertheless, when it comes to swimming an extended distance, with out the proper techniques you'll work twice as hard and get half as far.
Printing on gentle garments is much easier than printing white on darkish garments. On a light-weight garment, not as much ink is required to achieve good coverage. Additionally many times you are working with thinner inks. Ink varies in viscosity in keeping with how much pigment it has in it. As an illustration, a black ink is nearly at all times going to be printed on lighter colours, the pigments wanted for the black to indicate up are considerably much less then the pigments needed for a white ink to cover a dark garment.
Thus, you are black ink is far thinner and easier to work with. You can do nearly every approach fallacious when printing black ink on a white shirt, and there is still a great chance that your remaining print will look pretty good. Since the ink is thinner, it passes by the display mesh much simpler, with much less pressure, and clears the display better. (For these unfamiliar with the time period "clearing the display," this defines the purpose when all ink is cleared out of the display screen mesh and properly transferred to the shirt.)
So basically when setting up a display printing job that requires black ink on a white shirt, you should use the wrong screen mesh, have no off contact, and print with the completely mistaken squeegee approach and still get an "OK" trying ultimate print. Nevertheless, if these same unsuitable methods are tried when printing white ink, uh oh, game over! The unfortunate factor is, many printers begin out this way and train themselves completely wrong.
The truth is, this is how I learned. It is not the top of the world although!
The very first thing you will have to grasp and come to phrases with is the fact that white ink might be going to be the thickest ink you may ever use. To achieve a shiny white picture on a black shirt, the ink has to be opaque which in flip means thicker. Positive you'll find thinner white inks, or attempt to reduce the thicker ones, however you are defeating the purpose and you may find yourself printing twice as much to try to achieve the same result. On the other hand, in case you learn how to print accurately, then printing white is like taking a stroll in the park.
Earlier than we delve into methods, let's first talk about slightly bit about pre press and setup.
To properly setup a job using white ink you first should
perceive just a little bit on the way to choose the correct mesh size. As a result of white is
thicker, you need to print through the lowest correct mesh measurement that applies to
that print. When you try and print white by a higher mesh display screen which has
a lot smaller holes in it its going to make it much harder to push the ink by way of the screen. It's also not going to allow as a lot ink by means of the screen as a decrease mesh would.
Sometimes you want to print white via mesh sizes ranging from 110-156. Granted typically the picture dictates a high mesh count. As an illustration, since a half tone or advantageous line drawing can not hold on a lower mesh display, you will have to use a excessive mesh body and apply extra passes to achieve a shiny white. For the most half nonetheless, you may wish to use the lower meshes so that a bigger quantity of ink is deposited on the shirt.
The second a part of setup is to insure the screen is adjusted properly on the press. You need to make sure that you've got a correct off contact of about 1/8-1/sixteen of an inch. Since white is a little thicker, you could wish to go along with a barely increased off contact then normal, maybe round 1/eight of an inch. Off contact is the peak between the display screen mesh and the substrate you are printing on.
Proper off contact also allows the ink to be cleared from the screen mesh simply by releasing the mesh upward immediately after the print stroke leaving all the ink smoothly on the shirt. One thing that you additionally need to you'll want to apply when printing white ink is an off contact tab. This can be a small piece of material (ie. a penny, cardboard, paper, a chunk of plastic) that's the height of your off contact. This tab is positioned on the end of the screen body the place it hits the top of the neck platen and not the shirt. By utilizing an off contact tab, you insure that your off contact will stay by way of your entire print stroke.
The tab retains the tip of the screen up though you're pushing down on the mesh during the stroke. Without an off contact tab, you may discover that you've got a more durable time clearing the mesh because the screen wants to stay flat towards the shirt with ink stuck in it.
If you don't have the right off contact a few problems could arise. In case your off contact is too low you then will not be able to clear the display properly. You must see the display screen mesh bounce off the shirt and have the ability to see the ink and the shirt by means of a cleared display mesh. In case your ink stays in the display mesh and the screen mesh sticks to the shirt, if you pull the display screen up your ink will look very rough and elements could pull again off the shirt. For those who're having this drawback you might want to lift the off contact a bit bit. Also, this problem may come up out of your actual print stroke which will likely be discussed later.
On the opposite end of the spectrum, if you're off contact is just too high; you'll need to push down extremely hard on the squeegee with the intention to get all of the ink down onto the shirt. I have been out to outlets to help prospects who actually had nearly a half of inch of off contact. If your off contact is too high, not only will it's laborious to switch the ink onto the shirt, but there's a good likelihood that your display screen will not come down in the identical spot each time.
This could cause a blurry image or double pictures after a flashing. A proper off contact is extraordinarily necessary for a very good trying picture and a simple print.
Next let's take a look at technique. The majority of the technique within the display printing process involves the print stroke. This contains squeegee angle, strain, speed and release. That customary tendency of a brand new printer is to literally smash the ink via the screen by pulling the squeegee across the screen with an extremely low angle.
When utilizing thin inks, this impropertechnique could work because the ink passes via the screen so easily. Nevertheless, if tried with white, you will not solely have trouble passing the ink via the screen but also have very blurry photographs since you're pulling the screen mesh so hard. Your squeegee ought to truly be about an eighty-85 degree angle dealing with towards you. You must also focus your strain over and down on the print and not on pulling the squeegee in opposition to the mesh.
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Many new printers stand back from the press, you actually need to stand over the press to focus your strain down and not back. When your strain is targeted down, then you merely move the squeegee back over the print. With the correct squeegee angle, the entire ink will correctly shear by the image and over your screen. In fact it is best to be capable of run your finger over the design after its printed and barely any ink should show up on your finger.
Now let's talk in regards to the velocity of your print. Once we instruct printers to use the proper squeegee angle and pressure, the primary impulse they've is to maneuver the squeegee about the velocity of a turtle. If your velocity is just too sluggish you won't have the ability to properly release and clear the screen. After a print stoke, many beginners tend to sit again and have a look at their print, then slowly pull up on the squeegee not permitting the display mesh to bounce back up leaving ink still stuck in the screen. After a sooner stroke, it is advisable to nearly give the display screen somewhat pop with the intention to get the mesh to bounce again up depart a easy crisp print on your shirt. That is achieved by a simple flick of the wrist, the identical flick you'd make to insure that you simply pick up all the ink in your squeegee blade. Solely to create this pop and launch the display screen, the flick should be achieved slightly faster.
Lastly, when flashing in between passes, you should wait till the shirt cools down a bit until you print again. That is a lot easier to realize on a multiple station press as a result of it allows the pallets to cool down. On a single station press you'll have to wait a number of moments and wave your hand across the pallet to cool it down.
If the ink is simply too scorching from theprevious flash, you may have bother clearing the display because the ink will need to stick as an alternative of release the mesh. It could additionally cause ink to partially remedy in the mesh. Since white ink is thicker and also you apply extra layers of it, you MUST insure a correct closing cure.
White ink tends to reflect heat away instead of absorbing it in. This means that the ink and the entire print space should be cured from prime to bottom at 320 degrees for about forty five seconds. Clearly the easiest way to treatment white is in a conveyor belt dryer, nevertheless in case you are using a flash dryer you want to be sure that the whole design will get the identical quantity of heat.
One of the best ways to insure a correct cure is called the stretch test. Since your white picture shall be a bit thicker, this take a look at is simple to read the results. After your shirt is cured, merely take a small part of your design and stretch it slightly between your fingers. If the design sticks collectively like plastic and stretches properly, then it is cured and you'll continue with those curing parameters. Nevertheless, if the ink cracks or breaks aside, this implies the base of the ink is not cured properly and you need to increase yourcuring time for the shirt.
For some How To Do Screen Printing courses go to www.learntoscreenprint.com.au
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For some How To Do Display screen Printing classes go to www.learntoscreenprint.com.au
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