polijet

[apjjr]

Rip

Rip

Maybe I should rephrase this ...
I understand the need for a RIP if printing multiple colors where the dots must align correctly.
But, if I am only printing 1 color and have no need for dot alignment, why do I need a RIP?

Alex

 

[stuff4print]

No matter what system or workflow, there will always be people who work four times as hard to acheive what can easily be acheived with the correct tools for the job.

I can put a six inch screw into a piece of wood with a hammer, but it sure goes in easier and better with a screw driver.

 

[apjjr]

I don't think I'd try the hammer, but I will try the free screwdriver first.

 

[stuff4print]

When imaging the PoliJet plates it is a vital part of imaging to accurately control the ink density to about 35%. I do not believe Corel Draw has such a function.

 

[apjjr]

You're right about CorelDraw, but the printer driver software might have that function.
What does 35% density mean? Opacity? Not coverage. If it's film thickness, what's 100%?
Is that the name of a setting in your RIP software?

 

[hagar]

Maybe I should rephrase this ...
I understand the need for a RIP if printing multiple colors where the dots must align correctly.
But, if I am only printing 1 color and have no need for dot alignment, why do I need a RIP?

Alex

Guess you could get away with it, but a RIP is of benefit for several reasons.
1. Screening, Ability to set screening options as you require and ability to calibrate the output, guessing that with an epson this important.

2.Time, if you have a Print Ready PDF, do you really want to be spending time in corel to get the job out

3. Output. If your just printing through a windows driver then you have to use the settings for that windows driver, which is designed for mainly paper. RIPS drive the epsons direct, and can control the weave pattens, ink droplet size etc

 

[iCtP]

Maybe I should rephrase this ...
I understand the need for a RIP if printing multiple colors where the dots must align correctly.
But, if I am only printing 1 color and have no need for dot alignment, why do I need a RIP?

Alex

When printing with inkjet technology, different papers absorb the ink at different rates. Epson's own driver knows this and has profiles that adjust ink density (the amount of ink laid down), correctly for each ink and each paper substrate.

If you pick an alternative function for your inkjet printer, such as Polijet, JetPlate or Glunz & Jensen's iCtP then the ink can not be absorbed... SO the volume of ink that is laid down is critical.

A normal proofing RIP can output in colour composite only, or you can force the colours to Monochrome. Trying to make the image Magenta only doesn't always work, as a standard proofing solution / the Epson driver will use 25% Light Magenta in highlights to help balance the tonal range... This will not give great results..

A good RIP can be set to direct a single channel's output to any of the Epsons' printing channels (Depending upon the RIP). The Wassatch SoftRIP can do this, the Jetplate RIp and teh G&J PlateWriter RIP.
In addition the G&J RIP goes further, and, can set the transfer function of when a small dot becomes a medium dot, and medium to large, or how many large / medium / small dots there are in a given solid area.

Without this control, solids over ink and reverse text fills in..

Back to why a RIP is important...Irrespective of which solution you choose, other than using it to seperate your jobs, and directing it to the correct channel for outputting...it controls the volume of ink delivered to the substrate. Without it, you are likely to "FLOOD" the area with ink.
If the over inking is too server,the amount of calibration required to try to reduce it, will also reduce the number of levels of grey within the image, thus creating steps in the gradients.

If you ONLY print text and line work... the only artifact you are likely to see without the RIP, is some degree of the text becoming fatter, or reverses filling in.
But, as soon as you add solid areas, halftones or gradients the need increases.

 

[apjjr]

iCtP,
Thanks for the very helpful input. I feel enlightened.
I'm waiting to see if VIM Technologies is going to get moving with their attractive JT product. If they take too long, though, I'll probably go with G&J. I am currently getting ripped-off by a local print shop for my plates, but I can wait a little longer.

 

[iCtP]

Hi "apjjr",

You are welcome.

Please let me know how you get on with Vim, I saw them at Drupa and twice since. But nothing I've seen recently made me think, it seemed iminent .

M

 

[apjjr]

iCtP,
I'm afraid VIM JT is vaporware at this point. I just don't want to commit to a $25k system and then have them show up on the market 2 months later. I'll post any news I get on them.

 

[InkjetCTP_waste_of_money]

ICTP is correct, with the RIP points, the screening, single channel output, but you also need a means to calibrate the device which is why your tints are out at your 35% screen. You would have to include a photoshop curve or profile to adjust for this, and you would not get a stochastic or conventional dot. You would have a grayscale injet output which would not reproduce on the press.

Hope this helps...

 

[apjjr]

I have gone with a used HP 5100 and polyester plates and getting excellent results, so far in our 1 color shop. Total investment is about $525 for the HP and a box of plates. No changes on the press, either!

 

[stuff4print]

PoliJet

PoliJet

I notice that nobody has posted to this subject lately. If anyone is still interested, PoliJet now has one dealer in the US, and is actively looking for interest but at this stage only on the East coast.

 

[discountprinting]

The biggest problem I think is that there is a very small percentage of offset printers out there that are even aware of what inkjet CTP is, much less the quality that can be achieved, the much lower cost for both the equipment, consumables and production time for plate making. I have asked PIA/GATF and PIAG to educate printers on this topic but I think my suggestions fell on deaf ears....so pass the word on to all your printer trade associates...view this thread for even more info:

http://printplanet.com/forums/computer-plate/19645-tango-dotworks-should-g-j-concerned