TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The layer: comprises silicon, silica, or silica and at least one oxide including aluminum, zinc, tin, titanium and/or zirconium; has an average refractive index value of 1.10-1.50 (preferably 1.20-1.40); and has a thickness of 25-500 (preferably 250-350) nm. The substrate is a glass or plastic substrate. The coating (A) comprises at least one additional layer disposed between the porosity graded layer and the substrate. The additional layer disposed between the porosity graded layer and the substrate has: a refractive index of 1.20-1.50; and a thickness of 35-200 nm. The first layer: is non-porous; has a thickness of 50-200 nm; has an index of refraction of 1.40-1.60 (preferably 1.20-1.40). The first and second layers each have a thickness of 50-250 nm. The second layer comprises silicon, silica, or silica and at least one oxide including aluminum, zinc, tin, titanium and/or zirconium. The temperature above the first temperature is 500-800 degrees C, preferably 550-750 degrees C. Preferred Method: The step of preparing the composition comprises mixing a compound comprising silicon and oxygen (1-15 (preferably 1-10) vol.%), a polymeric glycol (1-20 (preferably 1-15) g/l of composition), strong acid (1-20 (preferably 1-15) g/l of composition), at least two alcohols (1-30 (preferably 1-20) vol.%), a balance of water and optionally a compound comprising aluminum and oxygen (0.1-10 (preferably 0.25-5) g/l of composition) together to form a liquid composition. The compound comprising silicon and oxygen is silanes, silicates, siloxanes or silanols, preferably tetraethyl orthosilicate. The step of applying the composition comprises spray coating (preferred), dip coating, brush coating, spin coating, roll coating or curtain coating the composition onto at least a surface substrate. In the method (C): during the applying step, the substrate is at atmospheric pressure and the first temperature is 30-100 degrees C, preferably 40-60 degrees C; and after heating, the coating is porous or after heating, the coating is porosity graded such that larger pores are located closest to the substrate and become smaller throughout the coating thickness away from the substrate.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The strong acid is nitric acid, hydrochloric acid (preferred), sulfuric acid or hydrobromic acid. The at least one of the alcohols is ethanol. In the method (C), when at least one of the alcohols is ethanol, the second alcohol is propanol, butanol (preferably n-butanol) or pentanol.    TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The polymeric glycol is polyalkyl or polyalkylene glycols, preferably polyethylene glycol. EXAMPLE - A liquid composition comprising tetraethyl orthosilicate (0.1-5 vol.%), polyethylene glycol (0.231-11.5 g/l of liquid composition), hydrochloric acid (0.444-8.88 g/l of liquid composition), n-butanol (0.1-20 vol.%) and balance of ethanol was prepared. The liquid composition was applied onto a glass substrate at 60 degrees C. The coated glass substrate was allowed to proceed to a tempering oven at, at least 500 degrees C. The coated glass substrate was heated and the tetraethyl-orthosilicate was converted into silica.