Last time I checked, vinyl doesn't hold up to the sun's UV rays real well. It will start to disintegrate and then the steel will rust. The rusting steel may leave iron rust stains on your clothing. There is UV resistant plastic clothesline, but as they say in the article, it's difficult to tie up and tighten. Simplest and easiest is always best. Cotton is organic and biodegradable, and it's not like you have to jack your foundation to change the clothesline after 15-20 years or however long it lasts.
Last time I checked, vinyl doesn't hold up to the sun's UV rays real well. It will start to disintegrate and then the steel will rust. The rusting steel may leave iron rust stains on your clothing. There is UV resistant plastic clothesline, but as they say in the article, it's difficult to tie up and tighten. Simplest and easiest is always best. Cotton is organic and biodegradable, and it's not like you have to jack your foundation to change the clothesline after 15-20 years or however long it lasts.