Unfortunately for us guitar players, abrasion is a fact of life for most materials that guitar picks are made from. And that means your favorite pick’s character may change as you use it. In fact, you might not even like a pick fresh out of the bag, but at some sweet spot in between fresh and worn. Welcome to the struggle!
The effect of abrasion appears to be an interesting intersection of two phenomena: surface texture change and geometry change. For a great example of these effects at work, here’s a quick comparison of a smooth and abraded Dunlop Jazz III:
Materials like nylon and celluloid develop a rough texture as they abrade, and this roughness excites harmonics in the treble region of the frequency response. Mechanically, abrasion also makes the edge thinner, and this appears to amplify the harmonic excitement effect. A nylon pick, the Jazz III becomes scratchy as it wears away and its edge also becomes thinner. Not only does this reward you with a wear pattern uniquely suited to the angle of edge picking that you use, but it also produces a more treble-infused sound that’s very easy to hear when you line the two picks up back-to-back like this.
For more analysis of guitar pick design and function, stay tuned for our imminent update to the Pickslanting Primer called… “Pick Design & Function”!