I noticed there were some questions on halftone colors and how to create them while doing some searching around, so I figured I'll create a thread for those still new to PS and wanting to know an easy way to make a half tone layer.
For this tutorial i used Photoshop CS, but it should...
I have created a screen in class last year and the printed tshirt looks like a painting.
We did something wrong.
Playing with the 45 dots per line and 100 dots per line, what does it mean? how does it associate with the actual printing of the tshirt?
I see 100 creates more dots, but but does this mean when I print I will have more detail or does 45 give more detail?
Quote:
Originally Posted by tpitman
To output halftones directly from Illustrator (or Corel, for that matter), you'll either need a RIP, a postscript printer, or use Ghostscript.
Here's how in Photoshop:
1. If you're working with 4-color, duplicate your file, open the duplicate, make sure the layers are flattened, then select Split Channels. This will give you a file for each of the four colors as grayscale.
2. Select one of the 4 files, and in the Image menu at the top, select Mode, and then Bitmap. You'll get a dialog box asking a method to convert, and you'll select Halftone. Press Okay, and you'll get another dialog box where you can specify your screen angle, lines per inch, and dot shape. Make your choices and save the file. Additionally, once you know what screen angle, dot shape and linescreen you want to use for that particular color, you can record an action for each separation and just play it for that color after you split the channels . . . pretty much push-button halftone seps the next time you need to make halftones. You need an action for each color since the screen angle will change for each one, unless you're doing spot color or simulated process. You'll need to make additional action sets for different linescreens (45, 50, 55, etc.) if you use different ones for any reason.
100 lines per inch will give you more detail than 45 lines per inch, but the maximum you'll ever likely print on a t-shirt might be 65 lines on an automatic press, and 55 on a manual. The 45 line per inch halftone is easier to manage, both in developing the screen and on press, though the halftone dots will be a little more noticable. The shirt material tends to soften the impact of the dot anyway. 50 lines per inch yields a nice print. Your exposure unit will also play a part in linescreen selection, as well as mesh count. You should have a vacuum blanket on your exposure unit if you're doing halftones to hold the best halftone dot definition.
Actually, you can use the same angle on all colors, regardless of the number of colors. Most screenprinters use an angle of 22-degrees and never have a problem with moire.
Actually, you can use the same angle on all colors, regardless of the number of colors. Most screenprinters use an angle of 22-degrees and never have a problem with moire.
You're correct for single color halftones or simulated process, but for 4-color process the angles need to be different to get the overlap of dots, although I read on one of these forums someone claims to use 75 degrees for all 4 colors and prints successfully. There are discussions elsewhere on this forum and over at screenprinters.net that debate different angle combinations that work.
Half tone Colors in Photoshop and Illustrator 
Re: Half tone Colors in Photoshop and Illustrator 
Re: Half tone Colors in Photoshop and Illustrator 
August is Member Appreciation Month at T-ShirtForums.com - 
