This has completely revolutionised greenhouse shading and is a quite new introduction. The Greenhouse Electrostatic Shading Paint material is called Coolglass. It is a liquid concentrate that can be diluted with water instantly to give any degree of shading required. It is an intense white and is formulated to reflect back from the glass those rays that cause scorching of foliage and overheating of the greenhouse when the sun is powerful. The diluted concentrate can be brushed on the glass or applied with a spray. The particles are so minute that there is no risk of sprayers becoming clogged.
The curious property of Coolglass is that once applied and dry (it dries almost at once), it cannot be washed off by even torrential downpours. The particles remain attached to the glass by presumably an electrostatic attraction. Coolglass can, however, be immediately removed by wiping oif with a dry duster just like wiping a blackboard. The shading can consequently be applied or removed much in the same way as a blind according to weather changes, but its cost is negligible in comparison to the cost and installation of blinds. It is also an advantage because the degree of shade can be varied and adjusted so easily. For example a weak dilution can be applied early in the year, and this oversprayed or removed and replaced with a stronger concentration as the sun increases in intensity.
It is non-poisonous and will not damage structures, but it should be applied with care to red cedar frames so as not to spoil the woods appearance. It is best applied with a brush in this case.
Coolglass is the only shading safe for plastic, since it will not scratch the surface on wiping off. Some plastics may not wet very easily. This can usually be overcome by adding a few drops of washing-up liquid to the diluted concentrate. Severely scratched or abraded plastic is best not treated with shading paint of any kind, since it may become ingrained and difficult to remove. Adhesion may be unsatisfactory on polythene.
Where the roof is not easily accessible, Coolglass can be applied with a brush or sponge tied to a stout cane or pole. It can be similarly removed by attaching a dry duster to a soft broom, for example.