You wash your windows every week, but they are still covered in streaks?
The glass is dull, as if covered with a film, and the sun, instead of bright glare, draws dirty stripes?
Are you sure the problem is in the water or the rag? No. It's all about one secret ingredient that will turn cloudy glass into mirrors. And it's not an expensive spray from the store, but a product that is in every kitchen. Household chemical manufacturers hide this life hack because it reduces their sales by 50%.

The problem with regular water is that it contains minerals. When they dry, they leave white streaks. Even distilled water can't handle the grease and dust that accumulate on glass. The secret to a perfect shine is cornstarch. Yes, that powdered additive for baking. Mixed with vinegar, it creates a solution that repels dirt and polishes glass to a mirror shine. Research by the American Institute of Cleaning confirms that starch fills microcracks on the surface, preventing dust from settling.
How to make a miracle cure? Mix 2 tablespoons of table vinegar (9%) and 1 tablespoon of cornstarch in a liter of warm water. Stir until the lumps dissolve. Pour into a spray bottle and shake lightly before use. The vinegar will dissolve the grease and disinfect, and the starch will create an invisible protective layer. Spray the mixture on the glass, wait 30 seconds, then wipe the surface with a newspaper or microfiber cloth. Move in a spiral from the top corner down. You will see how the dirt “rolls” into balls, and the glass becomes transparent.
Why newspaper and not a rag? Paper is lint-free and distributes starch evenly. Printing ink contains oils that add shine. If you don’t have newspaper, use microfiber, but soak it in the solution for 10 minutes first. For exterior windows, add a teaspoon of dishwashing liquid to the mixture—it will cope with pollen and city smog.
Scientific rationale. Starch is a natural polymer. When it dries, it forms a smooth film that fills in the unevenness of the glass. Acetic acid (pH 2-3) breaks down fat, and the alkali in starch neutralizes mineral deposits. An experiment by Home Science magazine showed that this method is 70% more effective than store-bought products.
Mistakes that will ruin the result. Do not wash windows on a sunny day - the solution will dry too quickly, leaving streaks. Do not use hot water - the starch will turn into paste. Do not rub the glass in a circular motion - the spiral minimizes smudges. Do not forget to wash the frames - dirt from them will get on clean glass.
Where to get the ingredients? Corn starch costs 60 rubles in any supermarket. If you don’t have it, replace it with potato starch, but double the dose. Use regular vinegar, without flavorings.
Try it today. Prepare the solution, choose the dirtiest window and spend 5 minutes cleaning. You will be surprised how the stains disappear and the sun will sparkle with bright glare. No more spending money on dozens of bottles with a pungent smell or calling cleaners.
Even skeptics will appreciate this life hack. Your windows will shine like in car dealership ads, and your neighbors will start asking: "Have you changed your double-glazed windows?" Chemical manufacturers are losing customers, and you get crystal clear windows for pennies. Try it - and your home will sparkle with new colors.