I'm note sure if this ist important for the better contrast:
Today Ibought a few Verbatim DVD +R Lightscribe media. This media are specified for 16x burns. My old one where specified for 8x burns. The new media are labled with "media version 1.2 / faster labeling on all lightscribe drives". Maybe the new 1.2 media are necesary for higher contrast.
The ring on the lightscribe side looks very similar to the old media, the only difference is that the small ring for the positiion marking is half covered with the chemistry on the data burning side and the other half not.
If pictures are needed I'd make some shots with my digicam...