10 Tips for Successful Simulated Process Printing

Screen Printing 25 Agustus 2011 Loading..
Screen Printing

Nothing´s automatic when it comes to making a simulated process print pop off the garment. Follow these insights to improve your process.

By Charlie Taublieb

When I hear the term "simulated process printing," I immediately think of black shirts. Maybe it´s because of my background of printing rock´n´roll shirts when I first started in this industry. That´s not to say that simulated process printing can´t be done well on other colored garments. In fact, if designed and separated properly, the printing will look good on every color, from black to white. However, simulated process is usually associated with dark colors.

Simulated process printing is a term that is often used but not always defined. My interpretation of the term is a print that appears to be full process printing — which creates a full color effect using halftones of cyan, magenta, yellow and black (CMYK) — but is not.

A simulated process image appears to have been printed in four-color halftones, but it actually is printed with however many specific ink colors are needed for that image. The colors may change from image to image, and the inks usually are opaque. The image — if designed and separated properly — can be printed on any color, including black.

To have a successful print, you must understand what it will take to make a good simulated process print or, in my case, a good black shirt print.


When I first got into this industry, we printed for rock´n´roll concerts. Today, but especially at that time, the 1970´s, anything other than a black shirt wouldn´t sell very well. If you are designing for bikers, X-treme sports or some pro athletes, black is the most popular color. I have yet to get an order from a motorcycle club for shirts printed on pink.


People wear black shirts because the colors stand out. To make this even more effective, design with large, easily identifiable images and bright colors. In designing concert shirts, we would simulate concert conditions to see if the shirt would stand out. We would illustrate our design using Craypas-oil based pastels on illustration boards, put them on the wall and view them from about 15 feet away with the lights darkened. If we could identify the images quickly, then we knew we had a sellable shirt. If not, we would re-work it until it was very visible.

When designing for retail, it is important for the design to catch your eye as soon as you walk in the proximity of it. If it doesn´t catch the eye, no one will go to it and it won´t sell. So, make your shirt design as large as possible.


When I previously mentioned an illustration board for working on a design, I was referring to a black illustration board. One of the tricks to having a successful design on black shirts is to design on black. The reason for this is you don´t print black ink on a black shirt. By using a black illustration board in the design phase, you only illustrate the highlights and mid-tones as the shadows are already there. The black illustration board provides the shadow, just as the black shirt will do for the finished simulated process print.

If you design on a light background, you will need to illustrate the highlights, mid-tones and shadows, which are needed for a light or white shirt. That means you will have to print a solid underlay to print on black because you didn´t design for black. You´ll end up with the equivalent of a heat transfer that has been directly printed to the garment. It will be missing the strong look and will require a black ink screen even on a black shirt.

When creating simulated process artwork on a computer, the best method is to start with a digital file that has a black background (the default is usually white or transparent) and then start working on your design.


Many people wear black shirts to stand out. In order to do that, you need to use bright ink colors. Lots of reds, yellows, blues, greens and purples, among others. As long as they stand out, the shirt will have a chance at success.

The contrast of the design is often the most overlooked area — but it´s probably the most important. Why? Because black shirts should be printed to stand out, which requires a lot of contrast, strong highlights and black shadows. Keep in mind that we are not necessarily looking for an anatomically correct image; we are looking for a design that will sell on a T-shirt. The fact that it isn´t anatomically correct means nothing to us.

How much contrast is necessary? The goal is very bright highlights and black shadows. How do we achieve this? By assigning a single point light source to shine on our image. The light can come from anywhere except straightforward, as straightforward light flattens a design.


Once the design is done, it is ready to be separated. When I first started out, we did all of our separations using a combination of hand and camera work. Between designing and separating, it was not unusual to put 30 to 40 hours into a design.

Today, with the software available, knowing how to do it by hand is not as important. A number of plug-in programs are available for Adobe Photoshop that make the separation process fast and accurate. There are even standalone programs you can use that don´t require Photoshop to run — any raster-based image-editing program will work.

The separation process may only take a very short time — based on the design and experience of the operator — or it may take hours. Whatever the case, digital seps done on the computer require a lot less work than we had to do back in the ´70s.

Many of the programs — Photoshop plug-ins and standalones — are available online for a free trial. Try several of them prior to purchasing to make sure you like the results. Remember that bad art, even when separated well, will still be bad art.


In choosing the resolution for my artwork, I prefer it to be two to 21/2 times what the LPI (lines per inch) will be. Typically, that will fall somewhere between 100 and 150, since I like to work with 45 to 55 LPI. I use a 61-degree angle for all separations and an elliptical dot.


Based on the mentioned LPI, I like to use the following mesh counts:

• 110 @ 35 N/cm for underlay on fleece. It sometimes moirés in the highlight areas, but that is usually covered by the colors going down on top of the underlay.

• 156 @ 35 N/cm for underlay on T-shirts.

• 230 @ 35 N/cm for all other colors, including highlight white.

I only flash white underlay. After the underlay, all colors are printed wet on wet. I rely on my colors blending together to give me a three-dimensional effect.


When printing on a manual press, I use a sharp, straight 70-durometer squeegee. It is important that the rubber blade be sharp and straight so you don´t eliminate the reason for using a high-tension screen. Print with as little pressure as possible so the ink sits on top of the shirt. If any ink shows on the inside of the shirt, or the pallet, then you are using too much pressure. For an automatic press, I like the 65/90/65 triple-durometer squeegees set at a 25- to 30-degree angle with minimal pressure.


I always use an opaque plastisol and try to avoid using fluorescent colors, which are very sticky and will build up and clog your screens, forcing you to stop and wipe them. When you do this, it will take about eight shirts to get the proper build-up of ink on the bottom of screens so the print matches the rest of the production run.

When starting a job, after registration of the screens is complete, strike off a shirt with four to six print strokes. The setup shirt´s colors will look very weak. The next shirt´s colors should look even stronger, and the shirt that follows will be your production run shirt. The colors shouldn´t change throughout the run unless a screen is wiped.


10_tips.jpgFor a simulated process design to stand out, you need a lot of contrast. That means strong highlights and black shadows, as we see here with the jaguar design. You are not necessarily looking for an anatomically correct image, just one that pops off the shirt.