I want to prevent my neighbors to see through my window but allow maximum light. Blinds are not possible there in the small one. The small window
Some transparent layer/membrane could work, not any permanent one.
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There are many films available to obscure glass -- frosted, patterned, etc.
They are self adhering and can be fairly easily removed. They come in a variety of sizes and can be cut to size.
Look for them in big box stores or window treatment stores.
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