This is the first on a series of posts I’ll be doing on grading to help give some of the tricks and tips I’ve learned over the years to help you help your customers help us all!
Today’s subject is light sources. I generally recommend that a higher lumen desk lamp, preferably halogen or compact fluorescent is used. Generally, the closer the source of the light, the better the results. I find that I see the most damage in the reflection of the lightbulb itself. Direct natural sunlight is also a tried and tested form of looking for tiny scratches.
What might look like a paper scuff might turn out to be a deep scratch under a brighter light. Look closely over the surface for anything that might be able to be felt with a fingernail tip. If it can be felt, it will be heard.
Other issues to look out for are cloudiness from outgassing of inner plastic sleeves and whitish streaks in the grooves from damage from bad needles. These will produce significant amount of noise, even if the disc looks undamaged otherwise. Manufacturing defects like bubbles, folds or bits of paper label or other impurities will have a significant effect on the playback of the disc.
Above all, these are all just part of a larger process in grading that should also include cleaning, play testing and smell-testing. I hope you find this useful and will gladly incorporate any more advice given in the comments below into the next in the series!