You can make a nice spectroscope using pizza box and discarded or damaged CD. There is nothing special about the pizza box except that it is one-time-use-and-throw box (after its use no one wants it really) and that it is broad but not very thick. You can use any other box.
Step 1: Open the Pizza Box
The pizza box that we used was 35 cm x 25cm and 2cm think. In fact you can make two spectroscopes using a box this big. We opened the box and folded it length wise and cut into two half.
There is hole cut in the box, presumably for moisture and heat to escape else the pizza would get soggy. We cut a slit on top of the box about a centimeter from the hole and a square window exactly opposite to this hole.
Step 5: Cut the CD or DVD - This Time Using Pair of Scissors
The spectroscope is now ready.
Step 6: Photograph the Spectra
Note - try to put the camera on a stand and switch off the flash mode.