It has been said that Caru was something of a stamp collector. This is in fact a bit misleading. He was by no means a philatelist, being happy to categorise stamps by their dominant colour. But he was aware that a stamp does have a certain inherent power; it gets a letter delivered.

Caru had a love hate relationship with the Royal Mail. On the one hand it brought him some cheques for the meagre royalties for this published works, letters from his few literary fans, and provided him with stamps for his collection. On the other hand it brought bad news from publishers and agents, summonses from the police, final demands, and threats of legal action from solicitors. In regard to the second category Caru did not see why he should have to pay for a stamp for a reply to a letter that he had not instigated. The concept was alien to him, and he started sending replies without a stamp. Then he had an idea. It came to him one weekend at The Forest Hotel (Coedwig Gwesty) in the Conwy Valley. Caru went there periodically to mix with others of an artistic temperament and to take the waters. At least that was what he told his wife. In fact these get togethers often involved wild parties in the woods, drinking of quantities of wine and absinthe, and the sampling of the local mushrooms. As subscribers to The Oddities know, this hotel operated its own hotel post service. Caru was impressed by the concept of printing one’s own stamps, though not to be used as a private postal service. He saw them as an opportunity to make his feelings known to those he had to reply to and had issues with. He talked his ideas over with artist Huw ap Lloyd, another regular at the weekend parties, and the other Huw soon came up with some artwork for the stamps.
There was a bit of disagreement between the two. Huw ap Lloyd was the founder (and sole pupil) of the school of art known as Oblongism, and Caru wanted square shaped stamps, just to be in charge of everything. After an arm wrestling match which ended in stalemate they compromised on a diamond format, .... and another round of drinks.

It was decided that four stamps, each with different wording, would cover most eventualities. The first one produced was destined for replies to solicitor’s letters and said “Who will rid me of these turbulent parasites” around the sides. The main illustration showed a tapeworm, head louse and flea. It was printed in peppermint green. While Caru had approved the artwork, he was dissatisfied with the final printing of the stamps. With his typical modesty he decided that his face was sufficient for the main image, and that the decorative background surrounding it should be dropped. The other three stamps followed that design format. For begging letters and requests for donations he had a “Charity, like chastity, is a rarity and best avoided” stamp in slate blue. Caru disliked having to reply to unsolicited mail, so often didn’t. Once the stamps were printed, and there was no enclosed reply postage he used a “Postage Paid by Addressee” stamp, printed in subdued ochre. Finally for replies to the police and the courts, a frequent occurrence, there was a claret stamp with “No longer, or no shorter, at this address” stamp. His reckoning on this was that using literacy license and the fact that he was still the same height as always he was. He was not making a false declaration.
 

However, Caru either lost enthusiasm for this, or simply over ordered the supply of stamps; or quite possibly he actually and eventually took note of the possible punishments that may arise from his continued use of his own stamps . Whilst cataloguing the Caru possessions The Caru Foundation unearthed a folder of complete sheets of these stamps and have allowed a limited distribution of these sheet to enthusiastic collectors.