Breathable exterior paint for cob cottage

[dllive]

Hi
Ive got a cob cottage, so its important the walls can 'breathe'. The walls are being lime plastered internally. The external walls need to be painted, so I want a breathable paint. Im sure there are expensive lime washes and breathable paints, but will the Sandtex paint do the job? It says its 'breathable': https://www.sandtex.co.uk/masonry/
Thanks