http://www.twowests.co.uk/ProductImages/AT2.jpg

Does anyone recommend a particular manufacturer or supplier of such ties as in
picture (not necessarily those - I just found that picture)

I have tried a number of different sorts and I finish up at the end of the
season throwing them away as they have gone brittle or even broken from the
strength/swelling of the tomato plant stems. I'm not expecting them to last
for years - I just want something which is reasonable quality - not too thin,
and flexible.