Need Help Urgent!! Anyone know how to build a smooth gradient without banding in illustrator.?

[Decomurale]

I am trying to build a white spot colour gradient. I have a job that needs to be printed in white on PET. The file is a rectangle and the white is gradient from 100% opacity tapering off to 0% opacity at the top. When I print this file it has severe banding caused by illustrator. Is there a way to build this spot White gradient in photoshop in 16bit? Anyone have experience with this? Thanks

 

[DerbyCitySignGuy]

This is more likely a limitation of your printer than Illustrator. Got any pictures of the print?

 

[dypinc]

We have gone through this before here so you might what to do a search. If I understand what you want to do you need to set Document Raster Effects Setting in Illustrator to at least 300ppi. This is if you are RIPing the Illustrator file or generating a non flattened PDF to RIP. You can test this by RIPing the file in Photoshop. You can go with a higher ppi but you need to test this to see if you can RIP it without making it a ridiculously large raster file. And you may be able to get by with less than 300ppi. Also most good RIPs have a setting to smooth out gradients.

 

[Decomurale]

We have gone through this before here so you might what to do a search. If I understand what you want to do you need to set Document Raster Effects Setting in Illustrator to at least 300ppi. This is if you are RIPing the Illustrator file or generating a non flattened PDF to RIP. You can test this by RIPing the file in Photoshop. You can go with a higher ppi but you need to test this to see if you can RIP it without making it a ridiculously large raster file. And you may be able to get by with less than 300ppi. Also most good RIPs have a setting to smooth out gradients.

We use Caldera and this gradient banding effect is very visible. I am not a photoshop expert so half of what you are explaining is unclear to me. My question I guess is how do we build a spot white gradient in photoshop. I don’t see the spot colour options. Only a spot channel option... hope I am being clear . Thanks

 

[ProColorGraphics]

We use Caldera and this gradient banding effect is very visible. I am not a photoshop expert so half of what you are explaining is unclear to me. My question I guess is how do we build a spot white gradient in photoshop. I don’t see the spot colour options. Only a spot channel option... hope I am being clear . Thanks

In Photoshop, you have to set it up as a spot channel. I have done this several times and it works good. On the Caldera usernet, they have a pdf guide on doing this. It would be way easier to follow than me trying to explain it. haha

 

[ProColorGraphics]

• Under the Channel Tab - Create New Spot Channel - Name it White. I have my opacity set to 50%. That ONLY determines how it displays on the screen.
• With that channel selected, create a selection of where you want the gradient to be.
• With the gradient tool, set to black/white for colors, draw out the gradient like you normally would. black=100% white and white=0% white opacity when printed

I then save them out as a high quality pdf and bring into Caldera. It has always worked for me.

 

[Solventinkjet]

Make sure your RIP is set to 16bit and not 8bit as this would cause gradients to be segmented. Also, in Illustrator, try making a rectangle with the white spot color and then overlay another rectangle with a black to (non-spot color) white gradient on top of the white spot color. Now turn the transparency setting to multiply instead of normal. Then print this file and see if it looks any better.

 

[Johnny Best]

I would use the Photoshop method but a lot of people use the object/ blend method in Illustrator and set specified step in blend options to at least 64 or higher to cut down on banding. Make a rectangle and fill with 100% white, make another rectangle and fill with 0% blend those together.

 

[rjssigns]

I would use the Photoshop method but a lot of people use the object/ blend method in Illustrator and set specified step in blend options to at least 64 or higher to cut down on banding. Make a rectangle and fill with 100% white, make another rectangle and fill with 0% blend those together.

This^^^^

Blend tool makes beautiful gradients with a minimum amount of fuss. I did a write up some time back on the exact procedure.

 

[shoresigns]

Without responding to all the misinformation that's being spread in this thread, here's the short answer:

There are two possible causes for gradient banding in your print.

One is that an 8-bit gradient has 256 levels of gradation, which is a small enough number that you can often see the steps of gradation. The best way to fix this is not by using 16-bit colours, because you probably don't know exactly how your RIP or your printer handles 16-bit — it probably gets reduced to 8-bit at some point before it becomes ink, and if that happens, you're back to 256 levels of banding. Some RIPs also may not support 16-bit files, and 16-bit files are an enormous waste of space for this situation. The right way to solve this is by enabling gradient dithering, which will eliminate any visible sign of 256-level banding. Maybe your RIP has a setting for this, but you can also enable dithering on a gradient in Photoshop.

Two is if your printer is not colour-managed (i.e. you don't have a spectrophotometer and custom linearized media profiles). If you're using stock profiles, gradient banding is often caused by the linearization curve that translates the digital file into actual ink output levels. This can cause banding even on dithered gradients, and the solution is to either invest in colour management, or trial and error with switching/adjusting your media profiles until you find something that works better.

 

[nate]

Caldera supports 16 bit processing. On the Print Screen click on Colors. The click on Miscellaneous. The change 16 bit Rendering to enabled.