As per my observations over many years, I have realised Wooden cloth clips are much reliable and long-lasting compared to the plastic ones. Plastics have a very peculair property, they loose their strength and become brittle when exposed to sun for long time. On an average a plastic clip may last for 3 or 4 months, depending on the plastic quality. But a wooden clip lasts much longer than that. They can withstand all temperature/season and do not loose strength. And even after it breaks or looses strength, it can become part of the earth and decompose easily.
If you are one of those eco-caring types, start using wooden clips. Dont worry about trees being cut for that. Coz all these wooden clips are made from waste wood pieces.