When you look at embroidery you are actually looking at the thread that was used to create it. This is why it always amazes me how little thought usually goes into the choice of thread by embroiderers.
Most embroiderers stick to using either rayon or polyester 40 weight threads. These are of course the most readily available and are the threads usually recommended by embroidery machine manufacturers, but they are by no means the only ones you can use.
Changing the type and weight of the thread that you use can dramatically change the look of your embroidery.
Solar active thread, glow in the dark, varigated and acrylic thread are just some of the other choices out there.
Solaractive is a UV embroidery thread that actually changes color in the sunlight. An extraordinary new thread designed and tested for today's high-speed embroidery machines.

This new technology gives the opportunity to have embroidery designs change from one color to another after exposure to the sun or any UV light sources.
The unique color changing effect was tested and proven to last more than 2000 times in and out of the sun (equivalent to the life of a garment).
These threads will work on any embroidery machine up to 1200 rpm with any bobbin thread (poly, cotton, etc.).
UV threads are machine washable, and can withstand up to 420° F (for patch embroidery or emblems).
Cones yield 3000 meters or 3300 yards and 1000 meters or 1100 yards also 200 yard starter pack (all seven colors). UV threads are 120 denier/40 wt.
For more info go to http://www.solaractiveintl.com/emb_thd.htm


You can make your special projects "light up"
with glow-in-the-dark embroidery thread!
Looks like ordinary embroidery thread in the daytime,
but turn out the lights and see the glow!There are many different brands out there but to see one try this website http://www.allthreads.com/moonglow.aspx

Variagated theads are a god way to add more color without having to add color changes.
To see some examples go to http://www.embroiderthis.com/rainpolthrea.html
Madeira manufactures a thread called Burmi Lana Thread which is made of a 30% wool and 70% acrylic. An innovative technology combines the advantages of a spun thread (softness) with those of a filament thread (evenness and high running length).



Because of it's thickness they recommend needle size 100 or 110 for use with Lana thread.
To see what a dramatic change it can make to your embroidery go to http://www.thesewphisticatedstitcher.com/malawoemth12.html
Remember when you use a heavier weight threads simpler designs with a much lower density work best, so it is usually preferable to use designs specifically created for heavier weight threads.
So good luck experimenting.