How To Spot Hairline Scratches From Cleaning On Coins
Hairline scratches are one of the easiest signs of cleaning to spot, but also one of the most misunderstood. They’re usually the first thing new collectors are told to look for, yet learning to identify them accurately takes some experience. If you’ve spent any time reading Reddit threads about cleaned coins, you’ve probably seen people confidently call something “hairlined” without offering much explanation.
This post is here to clear that up. We’ll break down what hairlines look like, how they form, and how to tell them apart from other fine lines you might see on a coin’s surface. By the end, you’ll know what to watch for and how to avoid getting stuck with a coin that’s been wiped, scrubbed, or polished.
What Do Hairline Scratches Look Like?
Hairline scratches are thin, shallow marks that often show up in clusters and usually follow a similar direction, but they’re not always perfectly parallel. The key is that they look intentional. Natural circulation wear tends to be scattered and random, with bumps, nicks, and uneven rub. Hairlines, on the other hand, look like someone dragged something lightly across the coin on purpose, whether it was a cloth, a brush, or even a finger.
They often show up in the open fields of a coin where someone tried to improve the surface. Under light, these lines reflect in a way that jumps out and doesn’t blend in with the coin’s natural luster or wear. Instead of telling the story of a coin that was used, they tell the story of a coin that was messed with.
Where Do Hairline Scratches Usually Appear?
Most of the time, hairlines show up in the fields, the flat areas of a coin that aren’t part of the design. That’s because those spots are the easiest targets when someone tries to make a coin look shinier or cleaner. They’ll wipe it with a cloth or brush, thinking they’re helping, but all they’re doing is scraping the surface.
You’ll sometimes see them on the portrait or other raised parts of the design (called ‘devices’ in coin terms). That’s even worse, because it means someone was aggressive enough to scratch through the high points of the coin, not just the background. A lot of times the scratches follow the contours of the design, almost like someone was coloring inside the lines with a dry rag.
The bottom line is this: if you spot thin, consistent scratches in the open areas of the coin, especially when they’re all facing the same direction, assume it’s been cleaned until proven otherwise.
Why Do Cleaned Coins Get Hairline Scratches?
Hairlines show up most often when someone wipes or rubs a coin, either with a cloth, their fingers, or even a brush, thinking they’re helping. Sometimes it’s an attempt to remove a fingerprint. Other times it’s part of a deeper clean to strip toning or dirt. No matter the reason, that motion (especially when the coin is dry or gritty) scrapes the surface.
Coins aren’t delicate, but they aren’t meant to be scrubbed either. What might look like a soft swipe can still leave behind visible scratches under magnification. Even a microfiber cloth can do damage if used the wrong way.
Are Hairline Scratches Always From Cleaning?
Not always, but cleaning is the main culprit. Some hairlines can show up from rough handling or coins rattling around in a bag. But those usually appear more random and less controlled.
The kind of hairlines that cause concern for collectors tend to look deliberate. They often run in the same general direction, cover larger open areas like the fields, and don’t match the rest of the coin’s wear. That mismatch is the giveaway.
What Should You Do If You See Hairlines?
First, take a step back and look at the whole coin. If the coin has wear but no tone or buildup in the recesses, and the fields are full of fine scratches, it’s probably been cleaned. If you’re not sure, try comparing it to similar coins using PCGS CoinFacts or another trusted source.
Hair lines don’t always ruin a coin’s value (especially if it’s a rare date) but they can drop it from a collectible piece to a details-graded coin in a hurry. If you’re buying, proceed with caution. If you’re selling, be honest about what you see. Most collectors will spot the cleaning eventually, so you’re better off being upfront. I’ve picked up coins that I later figured out had been cleaned, it’s heartbreak.
And if you’re unsure whether what you’re seeing are hairlines or something else, literally take a closer look. Grab a loupe or scope, look at how the lines behave, and keep reading the supporting posts in this series to sharpen your eye. Sometimes it’s not just what’s on the surface, but how it got there.