Intro: How to Make a Fiber Optic Light Diffuser With a Dot of Hot Glue
This is the method I use to make my glow-dot LED capes and flags.
*0.75mm fiber attached to an LED light source
*hot glue gun
*teflon or other non-stick work surface
*cold metal spoon in a bowl of ice - the thicker the spoon, the better it will work
Make sure your spoon is nice and cold first! You are using it as a heat-sink and it needs to be chilly.
The non-stick work surface is key here. I ponied up for a 3'x4' sheet of solid teflon, but you can make do with a large tempered-glass cutting board sprayed with PAM or some other kind of low-key silicone grease. I've even used solid shea butter in the past.
When your glue gun is nice and hot, stick a dot of glue over the fiber, right on the work surface. The fiber is thermoplastic, so it will bend very easily in the glue - as you bend it, you can see that light is now diffusing out through the glue dot.
Grab your cold spoon and freeze the glue dot! You can peel the dot and the fiber up from the work surface when it is set.
Note: This method is best used in conjunction with some kind of cloth - I have used sheer white poly/nylon organza in the past, and then sandwiched the dots/fiber matrix under another layer (quilted on) when I was finished. You might also use a heavier darker cloth as the backing and whatever sheer front layer you'd like. By themselves the dots aren't terribly robust, but in conjunction with the cloth layers they last pretty well.