Dithering problem

[dgofla]

I have a SP-300 and I've been trying to print some small decals for a customer. He has a drop shadow on some of his lettering and no matter what I do it comes out really bad. It's just a bunch of little dots and no matter what settings i try it doesn't change. It's a 3.5" x 1.7" inch rectangle at 300DPI saved as a eps file for Versaworks. A bunch of times from Illustrator and once from Photoshop. Anyone have any suggestions.

I've tried:
Increasing the quality in Versaworks
Each 'half tone' option in every combination I could think of under print quality.
Changing the rasterising settings in AI to 1080DPI for both raster and transparency.
Doing the same but under the save settings for an EPS in AI.

 

[Mainframe]

send me the file & let me take a look at it, signs@dwsignshop.com
maybe I can help
Bill

 

[printing238]

the heads could be out of alignment

 

[dgofla]

Everything but gradients print just fine. It seems something is wrong with VersaWorks or something. I can't seem to get it to print anything other then 72DPI. Should I try saving my files as something other then .eps?

 

[Bigdawg]

Okay - here is the reason why your gradients will print at 72 dpi but not higher. It's not Versaworks.

There are only so many steps that can be reproduced in a gradient. The longer or lighter the gradient - the more likelihood that you will see banding. At lower dpi you have more give in that number of steps and your gradient will appear smoother. As you go up in dpi, you also have to go up in steps to create the gradient. If not, you will see the individual bands where they were too wide to seamlessly blend into each other. Dithering can help, but there's only so much it will cover up.

It's mathematics, not software.

 

[bob]

What she said.

Unless you're printing at something over 1200 dpi, a foolish thing to do, a 300ppi image is counter-productive. Drop the image resolution down to 100-150 ppi or even 72-96 ppi.

As a rule of thumb you always want to print at a resolution at least 4 times that of the image being printing. This ratio and above yields the maximum dither and color efficiency. Thus if you're printing at 720 dpi you want to use images no finer than 180 ppi. Even 180 ppi at 720 dpi is too much, 150 ppi would be a better upper limit.

The unaided human eye is unable to detect pixelization at anything much over 120-130 ppi. Even at resolutions far less than that you'd have to hold the image right up to your eye to see it.

While it's no doubt counter-intuitive, a higher image resolution does necessarily not make for a higher quality print.

 

[dgofla]

Okay this is what I'm talking about.
These pictures are all at 'standard' quality and were saved as jpeg at the DPI mentioned. It's hard to see but all the drop shadows look the exact same. I also printed out each one on low and high qualities and there was no noticeable difference in the gradient.
Offsite pic replaced. Please observe our rules on photo posting.

Nothing I do seems to change all the little dots thats why I think it's some setting in VersaWorks or some encoding error in the file.

 

[petesign]

Sometimes I have an issue with drop shadows in illustrator not being as clean as ones in photoshop. Bring in each element to photoshop, rasterize the layer at the final size, and then do a layer style drop shadow from there. Flatten the image and save it as a .tiff and see what happens.

 

[dgofla]

Well I got a high-res .tiff from the customer and it may have helped a little bit. I noticed that the dots are all different colors, should I make sure the drop shadow is monochrome or does that really matter?

 

[Sticky Signs]

After doing all the fun file set up that's been mentioned in the above posts try this - Slow the print head down and set the printer to uni - directional. This will make a big difference in print quality especially on very tiny details.

 

[dgofla]

I tried uni-direction under the dithering/halftone options it did seem to make much difference. I don't know exactly what you mean by 'slow the head down' but I printed on high quality.