Faded receipt slips: is there a way to make the faded characters show up again after 4 years?

Try taking a photocopy, This can usually enhance the contrast between black and white and produce an image that is better than the original. You can play with the contrast settings on your photocopier to see which gives the best result.

I dont think there will be any new Rock Heros. There are too many Genres and sub genres now that its almost impossible for a band to make an impact the way Guns and Roses or Nirvana did.A band that comes out today will be automatically classified into one of those sub genres, possibly turning off potential fans because of their classification. Remember when Cheap Trick claimed they were New Wave? Well,rock fans that didnt like New Wave quit liking Cheap Trick once that comment was made. Todays generation of music fans will not allow a band to make an impact.Once they band starts selling a lot of Cds,start playing in bigger venues,and get more radio play, they are automatically labeled a SELL OUT. Sad part is,I think as far as todays music is concerned, I've turned into my dad. Every time I come to R&P, I'm hearing about all these bands and how great they are,but no matter how many times I've given these bands a listen, I just cant get into them.

I've had this problem more than once, and with a bit of luck and some intuition found a method to restore the thermal "image".

By gently heating the receipt at a distance with a hair dryer, I have been able to cause the original images to reappear. Note that too much heat will cause the entire receipt to darken, so you may want to test temperatures/distances on a blank area, such as the corner of the receipt.

Generally, a hair dryer on medium heat at a distance of 12" or so, waved slowly back and forth, can restore the original thermal image in under a minute. Your mileage may vary.