Royal Mail restrictions on small pots of paint

Some readers may have read the article in the latest "Miniature Warfare" pointing out a new, but little-known, restriction by Royal Mail whereby they will destroy consignments of water based paints if they exceed 4 x 140ml pots. I don't often buy paint by post for my figures, using mainly Citadel paints from the local Games Workshop. But my location will change soon and I will become more