Dumb q: Green work mat with measurements - General Electronics - Arduino Forum

I feel dumb asking this, but I'm just getting into electronics and in a ton of the videos I'm watching, people have what looks like a green either silicone or hard mat on their work tables, with white measurements on it. I tried searching a bunch for things like this but I haven't hit on the right search terms yet. What is it these folks are using?

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Share tips you have come across - General Electronics - Arduino Forum

Share tips you have come across - General Electronics - Arduino Forum

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