The former PTT wanted a series of 10 postage stamps about threatened animal species. I made the porpoise (50 cents) and the seal (70 cents). I had previously positioned the bar diagram showing how many porpoises washed up on Dutch beaches every year on the right. But then the seal leaps with his head into the bars, heading for an accident. It had to be the other way round. And then I had made the porpoise black, because of the pollution. It became brown. The chemical structure I had positioned on the seal which had to represent PCB (pbc was the largest threat), was also not entirely correct.