Normally a full-size (12cm) disc will be metallized out to the edge. It's possible, though, to have a full size disc metalized only out to the mini disc size (8 cm), leaving the remainder of the disc metal-free. We call it "clear substrate." If you have a title that really doesn't require a that much data, but you'd like the full 12cm "canvas" for your disc art , consider clear substrate. With clear substrate, you can leave transparent areas in your art.

Clear substrate is great for any project with a low amount of data, such as a CD single or a promotional piece. Clear substrate a good choice for many children's CDs or DVDs.

Imagine a disc package with a diecut window on the front panel, and through the window you see another window—with daylight showing on the other side. And in the window you see something floating there. What you're seeing is some art "floating" on the clear substrate. Add spot white ink behind the art to make it more opaque.

When you have determined what areas are to be done in white ink, you should create one or more layers with only the art that's to be in white, all done in one printing ink. If you have created white pixels over transparency, you'll need to make a copy of the white layers, with all the white ink converted to a pure ink color. Otherwise, the white pixels won't print because they're white, and in Photoshop, "white" means "paper."
Here's one way to convert the white into something that will print with white ink:
1. Turn off all non-white art. You should see white pixels with varying amounts of opacity, over the checkerboard transparency background. If you don't see this, You will need to get yourself a trans
parent background by either turning off the background visibility or by deleting the background piixels.
2. With the "marquee" tool selected, perform a "select all." You should see the "crawling ants" around your entire image, including the transparent areas.
3. Switch to the "move" tool, and "nudge" the selection with a cursor key, first one tap in one direction, then one tap in the opposite direction. This should convert your big rectangulat selection to one that contains only the white pixels.
4. In the "Select" menu, choose "Save Selection." and save the selection to a new mask (alpha) channel.
5. Crerate a new layer, which will contain the printable white art. Turn off all other layer visibility, leaving only ths new, empty layer.
6. We are now going to create art in a single ink color, in the new layer. Select the new layer, and with a pure process color set up and using the paint bucket tool, fill the entire layer with the process color.
7. Go to the channels palette, select the new mask channel you mede and perform "Image>Adjustment>Invert," and then copy the entire mask channel. (Fear not if you don't see colors when working in a single color channel. That's what you're supposed to see if there's only one channel selected. You're supposed to see in the channel where that ink color will go and how dense it will be, not what the color will look like. This allows you to work with very light colors [ light gray PMS colors or yellow, for instance] )
8. Turn on the color channel you filled previously, and do a "paste." You should see a black and white image showing all the areas that need to have white ink. When you turn all the channels back on, you should see the white ink art in that simgle ink color.
9. Name the layer something like "White Ink," so that we'll know which
When done this way, we (or you) can place your art into an InDesign master page, and, the white art can be duplicated on a new page, with only the white layers made visible through the "Object Layer Override" functionality built into InDesign