I used these on bare concrete, when I had my warehouse.
Guardian Air Step Anti-Fatigue Floor Mat, Vinyl, 3'x12', Black, Reduces fatigue and discomfort, Can be easily cut to fit any space https://www.amazon.com/dp/B0018KVG9K/ref=cm_sw_r_cp_tai_ofPeEbNV2NG52
Can be easily cut to smaller sizes.