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Fluid · October 25th, 2007

the angles I posted were Scott Fresnors not mine. Mine I keep to myself as its a lil trade secrete I got from Marc along with some tweaking of my own.

I also output to two imagesetters. I have a epaosnr1800 as a back up and only used for about a month waiting for my imagesetter to arrive.

Im not arguing with your info just adding to it.

Also - Using stochastic screening is a major plus when dealing with high end images as your not using halftones. Only issue is with lots of blends. Then I use both methods.

Here are some good articles

http://www.mrprint.com/images/articl...Secrets_v3.pdf
and
The M&R Companies :: Articles & Tips

ImageIt · October 25th, 2007

Quote:

Originally Posted by Fluid


	Fred, PS was short hand for Photoshop not Postscript

In this context, it is indistinguishable. Photoshop and illustrator are both built upon postscript foundations. Both programs include a full postscript interpreter.

Adobe illustrator is to postscript, what cobol was to assembler language. Each drawing command in the original illustrator had a 1:1 correspondence to the postscript language.

The screen button in photoshop has a 1:1 correspondence to the postscript transfer function.

When you convert an image to a halftone in photoshop, it will follow all of the postscript rules. Type in 75 degrees and measure what it produces. I'll bet $1 it isn't 75 degrees.

fred

Fluid · October 25th, 2007

Quote:


	In this context, it is indistinguishable. Photoshop and illustrator are both built upon postscript foundations. Both programs include a full postscript interpreter

Yes indeed

we could go on for days and many wouldn't know what were talking about. No need to keep it up. You and I both have a good understanding of the process you more so on the math end than I I dropped out of engineering in College as the math got too intense.

Now I'm a printer of 11+ Years.

Keep the ink moving

ImageIt · October 25th, 2007

Quote:

Originally Posted by Fluid


	the angles I posted were Scott Fresnors not mine. Mine I keep to myself as its a lil trade secrete I got from Marc along with some tweaking of my own.

Scott is wrong. How wrong? Have you ever seen the movie, my cousin Vinny. remember when Vinny says.

Vinny Gambini: How could it take you five minutes to cook your grits when it takes the entire grit-eating world 20 minutes?

Claiming to produce a 75 degree screen in a digital world is very mush the same thing. It is simply impossible to make a 75 degree screen with a raster device as much as it is to cook grits in 5 minutes.

Raster devices are like checkered boards. The number of angles draw across the board is very limited. 75 degrees simply is not one of the option.

In a prior job, i wrote a postscript spot function which created tear drop shaped spot function along with a none linear transfer function which created a gravure cell structure for chemical etching, which was calibrated to a linear halftone curve. Is silk screening any different?

One thing which i tried early on, was to rotate the graphic, crop marks and all a negative 7 degrees. When exposed, the 7 degrees would be manually corrected at exposure, but result in a 7 degree shift in screens. So far, i have yet to see the need.

Fluid, you have any samples to share? I came to this group looking for information, not giving it. So far screen printing process color has gone much easier than expected. It seems easy enough that anyone willing to invest in good equipment can make a decent product. Am i wrong?

fred

ImageIt · October 25th, 2007

Quote:

Originally Posted by Fluid


	Now I'm a printer of 11+ Years.

My first computer imagesetting was done using a univac 1108 and was programmed using punch cards. Many years of my life was spent transitioning traditional printing with digital imagesetting.

I'm one of the rare computer geeks which actually understand the reason things are the way they are. While i'm not yet a great screen printer, i would never match the screen of 2 inks. That's just wrong!

fred

rrc62 · October 25th, 2007

Quote:

Originally Posted by ImageIt


	Type in 75 degrees and measure what it produces. I'll bet $1 it isn't 75 degrees.

Is that why when I enter a screen value of 55, I get CMYK frequency values of 51.3, 51.3, 54.5 and 60.6? Is that Photoshop just saying...Hey, 55 won't work, but this will? Is it optimizing based on my screen and printer settings?

rrc62 · October 25th, 2007

Quote:

Originally Posted by ImageIt


	Fluid, you have any samples to share? fred

Hopefully I'll have something to bring to show and tell next week sometime. My ink and screens came today. Everything else will be here on Monday.

tpitman · October 26th, 2007

Quote:

Originally Posted by buzzbox


	i have a ? for you tpitman. it's been a long time since i have done straight cmyk. Common practice in photoshop is to duplicate your file and leave the original open (image - duplicate) then split your channels. select new action, record your bitmap conversion with a pause on screen angle.

Well, I'm not sure what the question was, but common practice isn't always what I do. Frankly, I tend to do things the hard way, and read software instruction manuals only under threat of physical pain. Splitting the channels and running an action is in fact a quicker and simpler way of doing it. Thanks for the info.

Fluid · October 26th, 2007

Quote:

Originally Posted by ImageIt


	Fluid, you have any samples to share? I came to this group looking for information, not giving it. So far screen printing process color has gone much easier than expected. It seems easy enough that anyone willing to invest in good equipment can make a decent product. Am i wrong? fred

I will bring my digital camera in on Monday and will take pics.
Most of my work is simulated or index yet I have some good 4-clr process.

Actually 4-clr process is easy yet does require good equipment in order to get a consistent quality result.

Proper Dot gain
Quality art/image
Quality films/halftones
Good Exposure unit.
Proper tensioned mesh frames
Mesh type
Tight registration press
Shirt weave

All these come into play with 4-clr process and actually any printing methods.

Also note the YMCK print order can change if the art/seps are not dead on. I have any times changed the order to get the proper reproduction on the shirt

ScreenWeb | Preparing Digital Files for Screen Printing

Scott F's article IMAGES - THE JOURNAL FOR TEXTILE SCREENPRINTING, EMBROIDERY AND GARMENT DECORATION

ImageIt · October 26th, 2007

Quote:

Originally Posted by rrc62


	Is that why when I enter a screen value of 55, I get CMYK frequency values of 51.3, 51.3, 54.5 and 60.6? Is that Photoshop just saying...Hey, 55 won't work, but this will? Is it optimizing based on my screen and printer settings?

Yes, when you entered 55, the software calculated the nearest possible screens which are mathematically producible for the resolution of your output device.

Attached are samples of the adobe screens, where the yellow screen has been moved around similar to the other samples.

fred

rrc62 · October 26th, 2007

Quote:

Originally Posted by Fluid


	Most of my work is simulated or index yet I have some good 4-clr process.

How does simulated or index differ from 4 color process?

Fluid · October 26th, 2007

they use more colors and specific colors form the design. Same principal of mixing colors on press to achieve secondary and tertiary colors. Usually needs 6 colors minimum to get a good print yet the more color the better, We usually print around 8

rrc62 · October 26th, 2007

Thanks Richard. That would be too many colors to be practical for me.

Another question....How do you guys prep a photo for 4 color process? Do you lighten the image overall to compensate for dot gain? Or maybe just lighten the dark areas? There looks to be a few ways to do this. Shadow/Highlight adjustment seems to be the best, but there is also the Curves adjustment.

I also see the Transfer button on the print dialog. This seems to be a dot gain adjustment, so by cutting back on the higher percentages, that should reduce dot size in the more dense regions. If this is how it works, would you mind sharing your transfer settings? Would a tonal adjustment to the shadows accomplish the same thing? Can't preview the Transfer settings, so it's kind of trial and error.

ImageIt · October 26th, 2007

I've always found it best edit the file at the images proper levels, then use the transfer function to adjust the levels to the press.

This thread describes what i'm doing.
Calibrated double stoke to eliminate snowflakes

Here is the latest t-shirt we've made using those settings.

fred

Fluid · October 26th, 2007

Nice print Fred.

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