Reading Oil Lines: What Natural Resin Looks Like

What to look at

Side-lit, natural resin appears as dots, threads or patches along the grain, with soft, irregular edges. A block that is "too perfect" in color deserves caution.

Common tells

Oil-injected or drawn lines tend to be too regular, dead-colored, hard-edged, sometimes with dye along grain. Oil lines are step one—not a verdict. This is ID science; verify in person or test.