Compo in Caithness wrote:

I have just finished a huge old bale of famer's string and would like
to buy some more. Problem is: where does one get huge balls or bales
of string from these days?
Was going to suggest e.g. Mole Valley Farmers, but they seem to only
sell synthetic twine, so online?

https://www.amazon.co.uk/Sisal-Baler-Twine/dp/B01N24H4RT