The Printing Process – Simplified
People ask us all the time, “How much do you charge to screen print t-shirts?” And we have to say, “Well, now that depends…” You see, every print job is different and pricing varies with volume, shirt styles, design colors, etc. To help you understand why we can’t just throw out a price without asking a good bit of questions, we thought we’d give you a little information on the various printing methods we use.
Screen printing is a technique that involves using a stencil to apply layers of ink onto a product. This process can actually be traced as far back as 960 AD during the Song Dynasty. But don’t worry….we’re not gonna take you back that far. We’ll just help you understand the basics while trying to keep you entertained. There’s a lot more work involved than most people realize.
First of all, a computer program separates an art design by colors and each one is printed onto a clear piece of film or vellum. For instance, to screen print this image:
It’s separated into the following three designs:
For each color, a different screen is needed. Screens are simply tightly woven polyester mesh fabric stretched over a wooden frame. Back in the day, silk was used instead of polyester. That’s why many people still use the term ‘silk-screening’. In ancient times, hair was even used but, again, we aren’t going there. Feel free to Google it if you’re real interested.
Before we can use a screen, the mesh has to be coated with a light sensitive emulsion and allowed to dry in the dark. The film is then laid on the mesh and placed in a machine that exposes it to ultraviolet light, which passes through the clear areas of the film and causes the emulsion to harden in those areas. No light can pass through the design itself so you’re left with a negative image of the design on the screen after the excess emulsion has been washed away. This leaves a clean mesh opening where the design is – just like a stencil.
Still with us? Good, good. Now comes the fun part. It’s time to print. We’ll keep this simple. There are different types of printing presses out there but the process is basically the same. Each machine has flat panels called pallets extending from it. The t-shirt (or other item to be screen printed) is stretched over this pallet and aligned for printing position. The finished screens are placed into press heads directly above each pallet. Factory or custom mixed ink is then placed at the back of each screen and, using what’s called a fill bar, this ink is spread over the screen, filling the mesh openings with ink. The screen is then lowered to the t-shirt and the operator uses a squeegee to push the ink through the mesh design onto the t-shirt. This process is done with each color until… Ta Da! The design is complete. All that’s left to do is to cure the ink by running the t-shirts through a textile conveyer dryer.
When it comes to artwork with four or more colors, it gets a little more complicated. Depending upon the complexity of the design, the printer may choose to use the standard method we’ve just described if the artwork has four colors. For instance, if the t-shirt only needs four large squares like this one:
Then it’s fairly easy to go ahead and make four screens and print each color. But most designs with lots of colors have much more detail than that. Think about a beach sunset or a wildlife scene. In these cases, either color process printing or digital printing is the standard method.
We could spend days explaining all the little intricacies of process printing and probably still not do justice to our experienced staff here who seem to have been born with mad printing skills. So, again, we’ll just stick to the basics. Remember mixing primary colors when you were a kid? Red and green produce yellow, red and blue make purple (actually magenta), and green and blue form a turquoise tint called cyan. Process printing uses semi-transparent inks in these secondary or ’subtractive’ colors, along with black, and overlays them in various amounts to produce a full spectrum of colors. This method is referred to as the CMYK color model…cyan, magenta, yellow, and the ‘k’ stands for key – which in this case is black. See, when you overlap these secondary colors, darker colors take on a muddied, faded tone. Black ink enhances these dark colors, creates a true black where needed, and improves the shadowing and contrast of the image. Get it? Black is the key to accurate process printing.
Now, back to the printing process. You already know about screens and that the ink is squeezed through mesh openings onto the t-shirt. Let’s elaborate on this just a bit. To print the squares on the t-shirt design above, a screen with fairly large openings in the mesh would be used so that thick, solid circles of ink are laid onto the t-shirt. All of these solid circles will combine to create the entire square. But for process printing, many different gauges of screens are used and the inks can be laid in very tiny dots of different layers to create all of the shades in full color designs. The initial color separations can also be manipulated to create halftones, which further controls how much ink is laid down for the perfect amount of color and tint. (Halftones can also be used in any screening process to create lighter shades or gradient effects.) So, by controlling how much and where the colors overlap, you can create an awesome design that looks very similar to a painting and has all of the subtle hues, lighting effects and shadows as the real thing.
Automatic printing presses are normally used to ensure consistency on item after item. But skilled artists, computer technicians, printers, and press operators (like we have here at Mirage) are indispensable. No design comes with its individual printing instructions. Only years of experience, a lot of trial and error, and a sprinkling of God-given talent can produce a full color processed t-shirt design that looks as good as the original artwork. Trust a professional. (In other words, use Mirage Promotions!)
Although we’ve been fairly brief with our screen printing narrative, we hope that we’ve given you a good idea of the time, expense, and labor involved. Maybe now our 24 piece minimum makes a little more sense. We would go out of business real quick if we had to burn screens all day long for one-piece t-shirt orders. So, how exactly do we handle smaller orders? And how can we offer our ‘Design Your Own’ t-shirts with no minimums? Well, we’re glad you asked these questions. Since you’re apparently paying at least a bit of attention, you probably remember that we mentioned a printing process earlier called digital printing. This is where this process comes into play.
Digital printing is the latest concept sweeping the industry; allowing for quick, customized orders with virtually no set-up and unlimited colors. Digital printing is more commonly referred to as direct to garment (DTG) printing because this process basically takes your design straight from the computer onto your t-shirt. Think of your paper printer sitting on your desk. Now imagine a marvelously souped-up version of it that prints on t-shirts instead of paper. Special software transfers the artwork to the printer and allows it to print large volumes of textile water-based inks directly onto the garment. These inks differ from the ones used in screen printing. Instead of lying on top of the t-shirt, they are more like dyes that are actually absorbed by the fibers of the t-shirt and become part of the garment. The ink is then cured to the garment by using a heat press or a textile conveyor dryer.
What a really cool process, huh? So why isn’t direct to garment printing used for everything? Well, there are a few drawbacks. Both the equipment and the required ink are quite expensive, and this has to be factored into the t-shirt price. But the main disadvantage is that only white or light colored shirts can be used. Unlike screen printing, where white ink can be laid down under design colors to make them show on dark t-shirts, no underlay is possible with direct to garment printing. Think about the printer on your desk again. You can’t put a black piece of paper in it and print out a red design. It just won’t show. But you can basically print out any color design on a white piece of paper. And any white in your design is actually the white paper showing through. It’s exactly the same with direct to garment printing.
With all that being said, advances in technology are being made every day. There is equipment on the market now that allows direct to garment printing on dark colors but the material must be pre-treated with a special chemical to allow the ink to adhere. Currently, we haven’t found a direct to garment process for dark colors that we’re willing to put the Mirage reputation behind. But this could change at any time, as we’re always striving to stay on top of current trends and technology as well as please our customers.