Once I selected the images I wanted to screenprint with, I had to create halftones in photoshop in order to turn my images into a screen. It’s best to have high quality images but halftones tend to be forgiving and you still get left with a lot of detail in the image if the quality wasn’t as good to start with.
Before converting the image to a bitmap, you have to convert the image to greyscale (Image-Mode-Greyscale), which changes the image to black and white. You can also go into ‘levels’ (Command + L) and alter how many dots or lines you want to have showing. The halftone dots are mainly just looking for the gradation from black to white. The more black it is, the more dots are in the area of the image so if its grey or white there’s equally less dots.
After the image is in greyscale you can create halftones. (Image-Mode-Bitmap). Photoshop will ask for what resolution you want your image in first. You can either scale your image up or down depending on the size you want it printed. I kept my resolution the same as I was creating all A3 size screens. Under ‘Method’ you then select ‘Halftone Screen’ which gives you a few more settings that I decided to mess around with.
Frequency - the smaller the number of frequency the bigger the dots / lines will be
Shape - Round / Line - These two are the most common shapes used
Angle - Doesn’t make a lot of difference on the round shape, but does on lines because it will change the angle the lines are coming in at
‘Frequency’ and ‘Angle’ are both settings that are most commonly used by screen printers. This allows the dots to go well with the screen you’re using once you get to the printing stage, and don’t create patterns that look bad / make the image unclear.
As I was making four screens it allowed me to experiment with different halftones to see what would look best once I print it onto fabric. The fabrics that I’m printing onto are all different materials so I figured it would be useful to try out different resolutions to be able to see what sort of halftone works well with each fabric individually.