Here at Adafruit, we love discovering new and exotic glowing things. Like moths to the flame, we were intrigued by these 'chip on board' ultra-flexible white LED Strips with a whopping 320 SMT LEDs per meter, soldered side-by-side and diffused with a thin silicone epoxy! They look a lot like neon or incandescent tubing or maybe really nice EL wire, but without the need for expensive transformers, glass tubing, or inert gasses. The strip itself is only 5mm wide, the casing is 8mm wide but can be removed.

Unlike addressable neopixel-dot strips, these lights have a continuous, light source, and unlike our 'Neon' tubing, they're much thinner and more flexible (but don't have a chunky diffused look) The trade-off for having a thin silicone cover and non-diffused tubing casing is that close up you can see the little hot spots between LEDs.
The silicone casing makes for a strong, durable, weather-proof casing. They're not guaranteed for dunking underwater or long-term outdoor exposure, but they're durable enough for outdoor projects like costumes, bike lighting, or festival decorations. Plus, with the adhesive backing, you can stick it where you please.
You'll get a 1-meter-long strip with two wires: black and red. Provide 3V at 200mA (bright) to 5V at 1.2A (very bright!), and the strip starts to glow.
This strip is powered from 5V, we also have one that is powered from 12V
Note these are not 'NeoPixel' LED strips; you cannot turn individual LEDs on or off. This guide on analog RGB LED strip control will show you how it works - you'll want a microcontroller with a PWM output and N-MOSFETs or a ULN2803 to control the power to the entire LED element.

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