http://www.amazon.co.uk/Bare-Conductive-Merry-Resistivities-Flashing/dp/B00GIWJSGG/ref=sr_1_12?ie=UTF8&qid=1452872553&sr=8-12&keywords=bare conductive
I now always have some conductive paint at hand for making blinky birthday cards.... you can just paint the circuit and stick an LED through the painted circuit and also attach a small battery. blinks for a few days and the circuit can even be writting or wahtever
I had originally bought something similar to get the pen (was cheap enough) and then used the batteries and led on self made cards
It might even have been that card set but I threw the cards away nearly immediately :-)
I've also used the paint to decorate presents with Leds. pack the present and then write on it with the pain and then give the writing a shadow with a different coloured edding to add effect. pop the led and battery in, let it dry and hand it over :-)
very important... it has very high resistance untill it's dry. so if at first you don't succeed it's just that the paint is not dry.
(probably)