How do I clean a CGC or CBCS slab?
Published Sep 14, 2026 · Updated Sep 14, 2026 · 1 min read
Short answerWipe the outside of the case with a soft microfibre cloth, dry or very slightly dampened with water. For stubborn marks, a small amount of plastic-safe cleaner on the cloth, not on the case. Never use solvents, alcohol, ammonia-based glass cleaner or abrasive pads, which cloud the acrylic, and never let liquid reach the seam or the label window. Scratches cannot be polished out safely; a badly scuffed case is a reholder job.
Routine cleaning
- Blow or brush off dust so you are not dragging grit across the plastic.
- Wipe gently with a clean microfibre cloth. Most fingerprints come off dry.
- For greasy marks, breathe on the case or barely dampen the cloth with water, wipe, then dry with a second cloth.
What not to use
- Alcohol, acetone, ammonia (most glass cleaners) — they craze and cloud acrylic.
- Paper towels and tissues — they leave fine scratches.
- Abrasive polishes, including many "plastic polishes", unless specifically rated for acrylic and tested on a corner first.
- Soaking — liquid at the seam or under the label window can reach the book.
Scratches and scuffs
Light surface scuffs sometimes soften with an acrylic-safe polish, but the risk of making a hazy patch is real. If the case detracts from display or sale, the grader's reholder service replaces it and the grade is unchanged. See What are Newton rings? for the other common cosmetic complaint.
Prevention
Keep slabs in bags; scuffs come from cases rubbing on each other and on shelves. Handle by the edges, and keep them out of sunlight, which yellows older plastics over time.
Written by the Rare Comics Collectors grading team. Spotted an error or have a question this guide does not answer? Tell us.