To achieve an effective whiteboard coating application, there are important things you need to keep in mind and follow when rolling whiteboard paint. One of these is creating a perfectly smooth substrate beforehand. The smoother and more uniform your wall is, the better it will look, and the easier it will be to write on and erase after the whiteboard coating cures. To achieve a flawless surface, you’ll have to eliminate any irregularities such as scratches, dents, and divots, no matter how tiny they may be.

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https://www.remarkablecoating.com/proper-method-when-rolling-whiteboard-painting/