CDs come i n two standard sizes. The most common is the full-sized 120 mm disc. Its little offspring, the Mini CD*, has a diameter of 80 mm and about a third the capacity. Variants of the mini CD include the clear substrate cd, and shape CDs such the popular business card CD.

For reference, a standard 120 mm CD-ROM holds about 650 megabytes, which is 0.64 gigabytes or 0.68 billion bytes. Mini CDs hold about 185 MB.


* Some people refer to mini CDs as "Mini Discs"—a proprietary SONY magneto-optical format.

Designation		Diam,(mm)	Capacity,MB	Capacity,(min)
				(Std PCM audio)
High Density CD		120	700	80
Standard CD		120	650	74
Mini CD		80	185	21
Business Card	Hockey Rink	80 x 65	40	4.5
Business Card	Rectangular	86 x 58	30	3.4
Business Card	Rectangular	86 x 56	18	2

For more info, see Compact Disc on Wikipdeia

Mini CDs (or DVDs) can work with either 3 inch/80mm packaging (we call this "mini dsic size") or regular "cd" size 5 inch/120mm packaging. They can also work with custom size or a taller "dvd height". The discs can be held with foam hubs, pockets, or trays. Booklets can be a more standardized size, or also made especially small in the 3 inch/ 80mm size.

Clear substrate discs are made by using the mini disc mold (so the same data size as a mini disc!) and clear substrate rather than the metalized substrate out to the edge of the disc. The result is a partially see through disc. The physical size is the same as a normal, full size disc, and as a result, it never gets stuck in a slot player! You can have a lot of fun with the art.