Our Premium Indoor Sports Tiles don't need to be installed with an underlay, but we do suggest one for added comfort and bounce. The underlayment acts as a shock absorber helping to protect your joints while at play. You can paint lines onto your floor, or you can use tape. We recommend using a two-part polyurethane paint to paint lines on your court. For any cut outs, you can use our tile cutter or a table saw to create the cutouts that you need.