A twinkle bulb is a special type of light bulb which blinks on and off for decorative effect. They are most commonly used on Christmas lights and other string lights, but can also be used for other ornamental purposes like electric jack-o-lanterns for Halloween and replica traffic lights.

What are twinkle lights called?

If you're considering adding some of these lights to your backyard patio, you've probably seen this type of lighting called many things including fiesta lights, party lights, string lights, and even festoon lights.

What makes fairy lights twinkle?

Twinkling sets also use a lot of bimetallic strip bulbs – typically every fifth bulb has a strip. The result of the bulbs being shorted out is that all be the bulbs in set see a higher voltage. This makes the entire strip shimmer in time with the flashing. That's where the twinkling magic comes from.