Thermal printers
"Thermal" printers are relatively cheap and can print on any disk. This doesn't cover up any branding and the existing graphics may interfere with what you want to print. Also, a cluttered existing layout can cause confusion between it and your added printing.

Still, this does look more "professional" than using a marker. The biggest downside is that such printing is either black or a single color. The key word is "single" since only 1 color can be printed at a time and changing colors requires changing cartridges!

Altogether, this isn't a bad way to label disks, and the ongoing cost of ink is fairly low.

Inkjet printers
There are inkject printers with special carriers that allow printing in full color directly on the disk. Good results require special "printable" disks that are a solid color, usually white. This effectively emulates the fancy printing found on a lot of commericial disks. Inkjet printable disks are widely available and cost only slightly more than regular disks.

The printers are more expensive than regular inkjet printers but not nearly as much as they used to be.

The main drawback is the ongoing cost of ink. The cost per disk depends on the printer used and how much of the surface is printed. 20¢ is about the minimum with the average being more like 60¢. If the entire surface is printed with an image as the background then the cost per disk could exceed $1!

Lightscribe^tm
Lightscibe^tm technology allows you to label the disk directly using the writer itself! Burn flip burn is their slogan and that pretty much describes the process. The same laser that burns the data also burns the label. Special drives, disks and software are required.

The resulting labels are a kind of tinted monochrome with a grayscale good enough for photographs. The most common disk color is a slightly greenish golden color but other colors are available as well. Lightscribe enabled drives are widely available and cost about the same as drives that lack this feature.

Lightscribe disks cost about twice what regular disks cost if you shop around, or a lot more than that if you don't! If Lightscribe is more widely adopted, the cost of the disks should come down, possibly to the point that they cost about the same as regular disks.

In the meantime, with Lightscribe DVDrs selling for 60¢ each in spindles of 50 (30¢ per disk more than regular DVDr), Lightscribe is already typically cheaper than full color inkjet printing.

Recommendations:
If you are just looking for something neater than markers at minimum cost, go thermal. If can settle for grayscale and are willing to pay 30¢ extra per disk, consider Lightscribe. If you want the best full color results and are willing to pay 30¢ to 99¢ extra per disk, consider an inkjet disk printer.
Part eight