If I hunt for specifics I usually call small shops: "Hello. Do you have washing lines? Oh, thank you."

Bigger chains usually has a website you can browse instead.

The value-add is that I can see the washing line before I buy it. Pictures just doesn't make it - they lie. And then I would have to live with a crappy washing line because what are the chances I would bother replacing it with another cheap random internet washing line.