Parts of the CD provide unique features graphic design and opportunities for desktop publishers and designers.
CD parts
In this article, we’ll take a look at the CD and analyze its manufactured anatomy, explaining how the different parts will affect your CD design. Knowing the environment you are developing for helps prevent unwanted surprises in the final product.
Main print area
Primary Disk Partition: This is where the audio or data is encoded. Colors printed on this surface will appear darker than on white paper. Depending on the ink coatings different amount of silver surface will show through. Higher ink coverage (generally darker colors) means you’ll see less of the reflective surface showing through. Less ink coverage, with print dots spaced more apart (generally lighter colors), will reveal more of the base surface of the disc. The only way to make something white on the surface of a CD is to print with white ink .
mirror strip
This is the ring area right inside the main print area. The mirror bar is not data-encoded, so it has a different reflective quality and appears darker than any other part of the CD. As a rule, the name of the manufacturer is engraved on the mirror strip, as well as the number or barcode identification, related to the master audio client. The effect of printing on a mirror strip is to darken text or images compared to the main print area. Right inside the mirror strip is the styling ring.
stacking ring
On the underside of each disc, this thin ring of embossed plastic is used to keep a small space between each disc when it is folded up for packaging and/or shipping. This prevents the flat surfaces from sliding against each other, which could scratch either the printed tops or the readable bases of the discs.
Although it is on the underside, some manufacturers cannot print over the ring stacking area due to the small «trough» created on the top surface when they sculpt their discs. Other manufacturers mold CDs that are smooth on top and print over the ring drive area without issue.
hub
This is the innermost part of the disc, made of transparent plastic, and includes ring stacking. Printing over the hub area is similar to the effect of printing on transparent media . The lighter the color, the greater the transparency effect due to the small, widely spaced print dots that are used to produce light colors.
With heavy ink coverage above the hub, transparency becomes much less noticeable. However, when printing through the clear plastic core, all colors will differ from other opaque surfaces on the CD.
Basic resolution of inconsistencies
Applying a white base coat to the entire printable area of the disc prior to printing the design reduces the darkening effect of the mirror strip and also reduces the transparent effect of the plastic sleeve. The white base (sometimes referred to as «white flow») acts as a primer so the final design looks more like standard case inserts, wallets, posters, etc. being printed on white paper.