Procedure:

1. Four sheets of goldenrod paper are taped together to form a banner (tape is on back of banner).  On the front of the banner, a message (such as SCIENCE IS FUN) is spelled out using clear Scotch tape.
2. The banner is then fastened above the heads of the audience, generally to the back of the demonstrator.  When Windex with Ammonia is sprayed on the banner, the background turns blood red, leaving the message spelled out in gold.

This demonstration may be used to introduce acid and base chemistry, providing a dramatic example of an acid/base indicator sold in copy stores.

 

----Contributed by Jackie Stewart, Mark Twain Section