I will definitely second this. The greatest tool you can have when looking if something is worth grading is a white or LED light. The light will allow you to see the cards surface much better and can show marks, smears, or scuffs that wasn’t visible before. If you’re someone who is interested in selling online, getting a light box is great. You can get them from as cheap as $20, and this offers the light needed to check condition of cards, and gives you a great spot to take pictures for online listings!