# can I print halftone w/o accurip epson 1430?



## binjoder (Apr 29, 2014)

Hi guys, I need assistance. would my epson 1430 print halftone film made in photoshop for porpuse of silk screen printting ?

Or it is must to use accurip?


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## threedims (Jun 5, 2014)

Yes. Turn image or each color of image into a grayscale (under the menu image/mode) and then to a bitmap image. When you change into a bitmap choose halftone screen and hit ok, then it lets you set your own frequency, angle and dot shape. now the dots are in your file. Look at them up close because they look funny at different magnifications. I use 45 lines per inch and 37.5 angle and round dot. I call this technique the poor man's postscript device.


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## chiste (Aug 8, 2011)

Don't forget your print settings.
I have a 1400 but I think it's the same thing. Works beautifully!
See image.


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## Simon12 (Jun 17, 2014)

threedims said:


> Yes. Turn image or each color of image into a grayscale (under the menu image/mode) and then to a bitmap image. When you change into a bitmap choose halftone screen and hit ok, then it lets you set your own frequency, angle and dot shape. now the dots are in your file. Look at them up close because they look funny at different magnifications. I use 45 lines per inch and 37.5 angle and round dot. I call this technique the poor man's postscript device.


Yes this is perfect. But I think there can be used other one instead of Bitmap if you don't have that.


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## binjoder (Apr 29, 2014)

mmmmmm, does photoshop give results better than accurip ??? or vice versa ?

opinion needed


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## binjoder (Apr 29, 2014)

threedims said:


> Yes. Turn image or each color of image into a grayscale (under the menu image/mode) and then to a bitmap image. When you change into a bitmap choose halftone screen and hit ok, then it lets you set your own frequency, angle and dot shape. now the dots are in your file. Look at them up close because they look funny at different magnifications. I use 45 lines per inch and 37.5 angle and round dot. I call this technique the poor man's postscript device.


what is the relation between LPI and the angel ???


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## threedims (Jun 5, 2014)

LPI is the size of the dot itself. The higher the mesh count the smaller dot you can hold in the screen. Note: 65lpi is a smaller dot than 45lpi. The angle, for screen printing, should not be traditional offset angles eg. 45 degrees. This will or can create a moire pattern in you print. better angles to try are 37.5 and or 22.5. since the mesh fabric itself is 90 degrees on the frame the offset angles of 15,30,45,90 and so on should be avoided as the dots will clash or be truncated at those angles. you really have to experiment with lpi to see how small of a dot you can hold. 65lpi is usually on a high mesh count such as 230 or higher. 45 lpi should hold on a 180 mesh


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## PositiveDave (Dec 1, 2008)

Photoshop gives poorer results than a RIP. 
If you are halftoning a 300dpi image to 50lpi, your cells will have 6 x 6px - 36 dots, so you can have 37 shades of grey - 6x6 plus white.
If you halftone on a RIP, that will use the dpi of the printer - so 1440/50 -~70px squares, smoother gradients and nicer prints.


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## LB (Jul 25, 2009)

That being said..brings me to what could possibly be another thread.
What kind of results can I get from using the Ghostscript interpreter,using a halftone produced by T-seps? (or Photoshop as previously described) You know Ghostscript is free, Accurip etc is $500 bucks. Is it really worth the difference? 




PositiveDave said:


> Photoshop gives poorer results than a RIP.
> If you are halftoning a 300dpi image to 50lpi, your cells will have 6 x 6px - 36 dots, so you can have 37 shades of grey - 6x6 plus white.
> If you halftone on a RIP, that will use the dpi of the printer - so 1440/50 -~70px squares, smoother gradients and nicer prints.


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## Omni (Mar 28, 2012)

PositiveDave said:


> Photoshop gives poorer results than a RIP.
> If you are halftoning a 300dpi image to 50lpi, your cells will have 6 x 6px - 36 dots, so you can have 37 shades of grey - 6x6 plus white.
> If you halftone on a RIP, that will use the dpi of the printer - so 1440/50 -~70px squares, smoother gradients and nicer prints.


Respectfully, I will take issue with you Positive Dave, as I respect your inputs in this forum.....You can get a halftone dot in Photoshop which is as clean, if not cleaner than Accurip.......I have run comparisons on both accurip and photoshop halftones and found that by resampling your original greyscale image in photoshop to 1200 to 1440 dpi that the resultant output was just as clean as the output from accurip.....Upon 30 times magnification in viewing the single dots on film, I found photoshops halftones to have less "squiggly" edges around the dots than those from accurip.......However.....I will admit that it requires a lot of trial and error to experiment with printer settings in order to achieve these results.....The problem of slight "banding" in gradients which is visible on the "macro" level, is more accurately seen by viewing them through a 30 times magnification. What is viewed through a 30 times magnification is this: along alternating lines of dots, the printer is depositing a few small droplets of ink which get scattered around the dots in alternating lines or rows of those dots, which when viewed by the unaided eye on the film output, create the visible banding.....This is the problem, which is dealt with by experimenting with the various Epson advanced printer settings, when printing directly through Photoshop.......Great results can be achieved, though not as conveniently as in Accurip, but at a far cheaper cost than $500.00, especially if one does not have the resources to afford the RIP


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## threedims (Jun 5, 2014)

I agree that PS can give great results with halftones. I really didn't believe it until I starting viewing the 1 bit tif files after they were ripped. Not as clean as you might think. After all, didn't adobe pioneer postscript?


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## LB (Jul 25, 2009)

threedims said:


> I agree that PS can give great results with halftones. I really didn't believe it until I starting viewing the 1 bit tif files after they were ripped. Not as clean as you might think. After all, didn't adobe pioneer postscript?


Excellent point. Yes, Adobe developed the Postscript language to work with the "new" laser printers that were coming on the market at the time. (I believe Steve Jobs played a part in convincing Adobe to do this) 
I have been advised by another recognized expert that re-sampling to 1440 ppi in Photoshop is the trick. This emulates what a rip does. An Epson 1430 with dye based ink is then capable of laying down enough ink without being boosted by a rip straight from Photoshop.
If you feel that you must process a Postscript file, take the PSD for your separations into Adobe Illustrator , process through the print menu to a PS file and open in Ghostscript (GsView) and then send it to the printer. Can't tell much difference with the naked eye between what I got with just Photoshop and this method. I set the printer to Best Photo and to Black and White.


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## PositiveDave (Dec 1, 2008)

Sorry, been AWOL for a while. @Omni - Postscript banding is the result of having low resolution halftoning - i.e. 300dpi You have a limited number of shades of grey, you can see the difference between adjacent colours, with 37 shades of grey they are 2.7% apart. @LB - resampling to 1440dpi would give a similar result. Most RIPs can supercell - use a matrix of say, 9 cells to increase the shades of grey, give more angles etc.


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## AdvancedArtist (Nov 23, 2006)

PositiveDave said:


> Photoshop gives poorer results than a RIP.
> If you are halftoning a 300dpi image to 50lpi, your cells will have 6 x 6px - 36 dots, so you can have 37 shades of grey - 6x6 plus white.
> If you halftone on a RIP, that will use the dpi of the printer - so 1440/50 -~70px squares, smoother gradients and nicer prints.


Just to clear this up.... PhotoShops RIP is as good or better then any RIP on the market. In my opinion better.
First lets correct some of the information presented in this post.











Here is how the math of RIPing works at 45 LPI with an image at 1440 DPI.










50 LPI would give 28.8 or rounded off 29 X 29 cells or 814 possible levels of gray scale.

So all you need to do in PhotoShop is upsample the image to say 1440 DPI. Then convert it to a bitmap select halftones LPI angle etc.. and your ripping as good as any RIP in the market.

In my opinion after years of research you are 100s of times better off ripping in your application were you can see, evaluate, edit, adjust and control your halftones.

Clean halftones are also in many ways a myth especially in screen printing. It comes down to resolution RIP in PS at 2400 DPI and you will see very clean halftones. 24OO DPI is one of the standard resolutions in commercial RIPs.

But if you take a deeper look do you really think you are going to get very round dots on the other side of this material?










Which would could be translated into these dot shapes










Just sayin


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## sben763 (May 17, 2009)

When set properly photoshop gives the same or better results. I have done more research on this then I care to admit. After getting photoshop set (either 1440 or 2400) can't remember and printing the same design, at same LPI and same angle I laid them on top of each other and side by side viewing with a PC microscope photo shops dots were slightly smaller but had better shape. Accurip a dots had more jagged edges. The only Rip that can do what I call super cells is Filmmaker. Using Tom's example above with the 4x4 example above. 5 shades of gray. In Filmmaker each cell can have 3 dot sizes. So 3x3x3x3 that will cover the variables. So that same 4x4 cell now is 81 shades of gray while all other Rips can only produce 5 shades. 

All graphics, rips only print 1 dot size from the epson printer. Epson made their printer with variable dot technology. Most of them have this. While some only produce 2 dot sizes(1900). Others create 3 dots sizes(1400). The 1430 with a new firmware now has 4 dot sizes but if you have the firmware it shipped with then same as the 1400. For those of you with refillables don't update because some of the CISS, refillables won't work with new firmware. 

What someone needs to figure out is how to produce the multi size dots with a graphics program.


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