How small does this fold down?

Exact folded dimensions aren't specified — test the fold depth against your storage space before ordering. It's designed to be portable, so it'll be considerably more compact than the full 48" × 18" footprint when closed.

Will this mat stain or hold fluid permanently?

The hard panel surface resists most shop fluids, but any absorbent seams or crevices can trap oils. Wipe up spills immediately and rinse with water to keep the mat in good condition long-term.

Can I use this outdoors or just in the garage?

It's rated for general shop and work use. Prolonged outdoor exposure or direct sunlight may affect durability over time — storage in a garage or covered area is recommended when not in active use.