Hi Rob,
Try this site.
http://www.amnh.org/education/resour...ectroscope.pdf
It may provide a template for a more substantial s.scope made of cardboard or ply.
I have made several of these with my students and it suprises them how much detail can be seen of energy saver lights.
I have even hand-held a 'happy snap' ccd camera to image the spectra seen.
I have posted about this 'paper spectroscope' here before, but can not find it.