As a retired A&P, during my career I worked at a flight school where cutting open oil filters and examining the element material with a flashlight was and is a good way to see if the engine IS making metal. Great suggestion for pilots performing their oil and filter changes.
And don’t forget to check the screens…rqd by 14CFR 43 App D…the big chunks are on the screen!
I clip the metal strip holding the ends of the filter elemet with side cutters. and pull out in one continuous piece and examine the side that the filter flows through (outside In I believe) and that way you don’t introduce more potential contaminates onto the element and I always run a magnet along to pick up material, not just when I see a potential issue.
The best tool I have found to cut the media out of the housing is a cheap bread knife. Far better and safer than a razor knife.