J52
Decorators Caulk from any DIY store. You will need the squirting gun as well. Make sure the gap is clean squirt the caulk in and after a couple of minutes, whilst it’s still pliable smooth over using a gloved finger. When it’s dry you can lightly sand and paint.
This is correct, however, I now use a dampened sponge to smooth it over because it works better than a finger.
