Greenhouse shade paint advice needed

[JP1987]

I’m hoping someone could advise on shading for my new greenhouse. I understand that many growers recommend aluminet 50% shade cloth which I’m having trouble finding at a reasonable price in the UK, I can only get 75% which I think would be too much shade. I’ve been looking at the white paint you can apply to the glass and wondering if anyone has any experience using it? The fact it becomes more transparent in wet weather seems like a plus in my climate and I would guess the white colour might have some cooking effect. My other option would be the green or black shade cloth but I would be concerned the space would get too hot. Any help would be much appreciated!