A blue sky full of billowy clouds is a cheerful scene to look at, especially if it's painted on the ceiling of a nursery, bathroom or covered porch. Faux finishing a soft impression of clouds in the sky is simple, especially if you recruit a partner to share in the overhead work. The greatest part about this project is that there are no real mistakes. After all, no two sky scenes are the same, so let your imagination float into a fluffy cloud.
Prepare room to paint ceiling. Move furniture as needed and cover with dust sheets. Tape sheeting to walls close to ceiling all the way around the room. Use dust sheets to protect floor. Remove any light fixtures hanging from ceiling.
Using roller, paint ceiling with the lightest blue colour, covering completely. Use brush in corners as needed to protect walls.
Mix medium blue paint 1:3 with glaze. Using brush, slap and rub glaze/paint mixture around ceiling unevenly. Apply two coats in places if desired.
Mix white paint 1:3 with glaze. Using sponge, softly dab white clouds around ceiling.
Mix a second batch of white paint 1:1 with glaze. Using sponge, strengthen the colour in some parts of the clouds.
Finally, using full strength white paint, add a few strong white areas to the clouds.
Choose one shade of blue that is a medium blue and another that is much lighter blue-grey. For white, use an off-white shade that is light but not bright or stark. Use less paint with each successive coat. The more light coats you apply, the more ethereal and delicate your sky will look. You can always add more paint but it's difficult to take away. Some spots in the sky should be opaque (more paint) and some spots more transparent (more glaze). Work quickly enough that the dabbing doesn't dry and leave hard edges that are difficult to blend. Overlap the dabbing, blending and smoothing. Do not substitute cellulose sponges. They make hard-edged patterns that are repetitive and difficult to integrate. Try using a wad of soft crumpled cheesecloth or even a bunched piece of cling film to make soft clouds.