Shiny vs Dull Media

Is Shiny media better than Dull media ?

Why I ask. I have a DVD Player that cannot play CD-RW but is able to play DVD-RW. I look at the media and saw that the DVD-RW was much shinnier than the CD-RW. The DVD-RW was even shinnier than my DVD+/-R.

So my simple thought is that shinnier = better. Want to seek expert advice on this.

Thanks again for helping this newbie.