UV Printing White Color Separation

What/Where is the UV Printer?

The UV Printer is part of the Fab Lab, not the printmaking department, although printmakers might find this useful. This process is essentially the same as Spot Color Separation.

Why do I have to separate the white in a photo?

Just like a regular printer, the Roland LEF-300 UV Versa Works printer does not print white. You have to tell it where the white is to print. You can do this with spot color as you create an image (say, in Illustrator - see page 9 of the manual) or you can separate out the white after the fact (e.g when printing a photograph)

You can also do this with gloss and primer. Simply name the channels:

RDG_GLOSS
RDG_PRIMER

How do I do this?

1. Open your image in photoshop and change your image mode

IMAGE > MODE > CMYK

2. Channels

Make sure you can see the Channels Menu at the right side. If not visible, Top Menu > WINDOWS > CHANNELS.

3. Make your spot channels

Find the white in the photo using Top Menu > Select > Color Range.

3A. Color Range Settings:

Select: Sampled colors
Localized Color Clusters: unchecked
Fuzziness: this depends how liberal you want it to be with what it considers white. A smaller number means more picky (white only) and a big number means less picky (white, greys, light pastels, etc)
Selection preview: None (this doesn't really matter, but I find this the most clear)

3B. Click the dropper on the whitest part of your image

4. Spot Channel

With your color range still selected, make a new spot channel by pressing on the Channels menu in the top right (the 4 lines). Press "New Spot Channel."

4A. Spot Channel Parameters

Name: the name MUST be exactly this:

RDG_WHITE

Color: It actually doesn't matter what color you pick. As long as you name the channel properly as per above, it will print white. I usually pick a color that will stand out a lot so I can see if I made a good selection.

Solidity: I usually put this between 40% and 70%. This is essentially the white's opaqueness.

4B. Optional: Edit your channel

After you have made the channel, you can also draw on or edit (e.g. erase) the channel to add more white, or take some away. Make sure to hide (press the eyeball) all of the other channels when doing this.

5. Save as Photoshop PDF.

Make sure Spot Colors is checked off.

6. Printing on the UV printer

Print as per usual.

Make sure under Quality:

Mode is set to White > CMYK or Cmyk>White