What material is best for making hair clips?

Sometimes. Depends on a few things.
Any clip that holds hair in place will leave some mark if you wear it long enough. That's just physics. The question is how bad, and how long it lasts.
Bow clips — especially acetate ones with a spring hinge — tend to be gentler than you'd expect. The clip spreads pressure across a wider surface. No single point digging into your hair.

What actually causes dents

Tension. Not the clip itself.
If you're pulling hair back tight before clipping, that's where the crease comes from. The clip just holds whatever shape you created. Wear it loose and relaxed, the dent is barely there.
Metal clips with narrow teeth are the real culprits. One thin edge pressing into hair for six hours — that leaves a mark.
A smooth acetate spring clip doesn't have teeth. Nothing to dig in. That's the difference.

How long does the crease last

For most people, 10 to 20 minutes after taking it out. Run your fingers through, maybe flip your hair upside down and shake it. Usually gone.
Fine or freshly washed hair bounces back faster. Thick or product-heavy hair holds the shape longer.

Bottom line

A bow clip worn loosely, on dry hair, for a few hours? Minimal crease. Nothing that doesn't shake out in minutes. It's one of the more gentle ways to hold hair back without a rubber band pulling and snapping through.

Honestly, yes — these work really well for finer or more delicate hair.

The clip doesn't grip by force. It holds through even pressure along the shaft, so there's no single point digging into your hair or scalp. If you've ever had a metal clip leave a dent or snap a few strands when you take it out, this feels pretty different.

That said, a couple of things worth knowing:

Don't yank it out. Slide it open first, then remove. Takes two seconds and makes a real difference, especially if your hair is already fragile or prone to breakage.

If your hair is very fine and slippery, the clip might loosen throughout the day — that's less about damage and more just physics. A little dry shampoo at the root helps it grip better.

For damaged or post-bleached hair, the smooth acetate surface is a lot kinder than metal teeth or rubber-coated clips that catch and pull. Most people with color-treated hair find it one of the safer everyday options.

For a lot of people, yes — and the difference is pretty noticeable.

Nickel is one of the most common causes of contact dermatitis. That itching or redness you get after wearing certain accessories for a few hours? More often than not, that's nickel reacting with your skin.

Regular metal clips and even some plastic ones have metal components — springs, clasps, pins — that can contain nickel. You might not even realize it's there until your scalp starts irritating you.

Nickel free clips remove that trigger entirely. No metal touching your skin, no reaction.

Cellulose acetate clips are a good example. The material itself is plant-based, and the hardware is either nickel free or minimal. A lot of people with sensitive skin switch to acetate specifically because of this — and most don't go back.

That said, skin sensitivity varies. Some people react to dyes or other materials too. But if nickel is the issue, switching to nickel free clips usually helps pretty quickly.

Worth trying before writing off hair clips altogether.