They performed the tests under "optimal" conditions, i.e. well placed labels (centered, no bubbles) and short term storage under office conditions for 6 label types from 3 vendors (Avery-Zweckform, Herma and Sigel) on both CDs and DVDs. The physical properties (unbalance, jitter and planarity or "angular deviation") and error rates (BLER or PI Sum 8 ) were measured with a CATS scanner and other devices by Audiodev before and after the labels were applied.
Here a short summary:
- Thinner labels affect the media less than thicker ones
- CD's are not noticeably affected by well placed labels (N.B. this is for scans @1x).
- BLER, 3T-jitter and unbalance weren't significantly affected.
- Angular deviation more than doubled though (typical: 0.8° -> 1.8°), and exceeded the specs (max. 1.6°). This may cause problems at high reading speeds. - DVD's are essentially destroyed by most labels- PI Sum 8 > 1000 (from 10) and DC-jitter > 13% (from 8%) are typical.
The high information density leads to strong reactions to the increased angular deviation, particularly in the outer parts of the discs. Only one make (Herma 8994, a silver plastic foil) was "OK".
These results (for the most part) are probably not surprising to forum-dwellers, who have a general suspicion of anything more massive than a Sharpie-line on their discs, but it's interesting to see concrete numbers. Personally, I do use labels for audio CDs and some video CDs and will continue to do so for home use. CDs "stored" under sub-optimal conditions, e.g. in a car, shouldn't have labels applied.
G
