Can I use a brush to spread this product or does it have to be poured?

A brush or other tool (art stick, spatula, resin spreader) may be used to spread epoxy resin – and may either be disposable after curing or reusable – see tool cleaning above. NOTE: Self-leveling issues may occur if the epoxy resin is spread too thinly over the surface. Spreading thinner than 1/8" may possibly cause surface dimpling, craters, or "cat's eyes.”