A quick overview of the color separation process with screen printing (aka: Silk screen, & serigraph) For a more in-depth study check out the Screen Printing Glossary (here) by the American Screen Printing Association.
The body of work that I have been developing is somewhere between the realm of traditional "analog" art and digital collage. This process fits my goals well. I will write more about the content of the work on a later date, but for now I want to show the process.
The first step is to get an image that you want to print. For me that means making a digital collage in Photoshop.
Below is a crop of one of the collages, showing 3 of the 5 eggs that will make the composition. I am trusting you, internet, not to take this image and claim it as your own. Don't do that. That's rude. Besides, it's a rough one, not very refined, you can do better.
Next you have to separate the layers of your image into the CMYK layers. C for Cyan, M for Magenta, Y for Yellow, and K for key (or black). This is a standard print setting. For images that are digital, and going to stay that way, many artists make the work in RGB mode (Red, Green, Blue) which is most appropriate for how colors are combined in light to make a full spectrum. Many dancers or theater folks understand color theory when it comes to light and how it's very different than color theory in physical pigment.
Once the colors are separated into their own layer files they will look black. This is to give the viewer an idea of where the color pigments sits on the surface of the canvas (the substrate... can be paper, background, etc). For screen printing you need to then convert these files into a bitmap. That will simplify the image in to a series of dots or ellipses. During that conversion you have to change the direction of the dots so a pattern wont appear as a result of the layering and threads on the screen. You also have to consider the thread count of the screen you will be using, and the level of detail in your image. That will determine the dpi (dots per inch) of the bitmap. For mine, I have a 305 thread count screen, and a lot of fine detail and color mixing to do so I put the dpi at about 175 (a little more than half the thread count is a good general guide line). I am using a toner printer, not a large format photo printer. This is about as good as I can get it, but using a large format printer would give one better results.
Next the layers are printed out on transparent film, and burned into the coated silk screen.
It would benefit you to label your layers, especially of they don't look very different from one layer to another. The black toner will block the light from exposing some areas of the coated screen. Once the emulsion is done hardening from exposure to light, you rinse out the screen which will reveal the parts that were protected by the toner. Those areas will wash clean.
Next, I generally try to print the image by starting with the lightest color, and building to darkest. Below are images of two prints in progress that already have the yellow, and cyan layers on them.
And there you go. I hope you found this process post interesting. Please feel free to reach out if you have any thoughts or questions! Thanks for reading.