Brickwork.
In general the bricks used for normal building works are:
Commons which are dense and smooth. To paint this type of brick is not straight forward as keying onto the brick surface can be difficult.
Because of this, the surface needs to be keyed and this can be done by either sweep sand basting or acid etching.
Once the surface preparation has been carried out and the surface is clean, dry, and free from other surface contaminates, the selected paint manufacturers masonry paint can be applied by following their specific recommendations.
Andura Coatings. https://www.andura.com
Dulux Trade. https://www.duluxtradepaintexpert.co.uk
Johnstones. https://www.johnstonestrade.com/product/pliolite-based-masonry-finish https://www.johnstonestrade.com/products
Sandtex. https://www.sandtexpaints.com/uk/masonry-paint/ https://www.sandtex.co.uk