Non-Marking Shoes Test
Flip the shoe over so the sole is facing up. Press your thumbnail or fingernail into the sole and observe if the sole is dented from the pressure. If the sole is dented momentarily, the sole is considered soft and is likely a non-marking shoe.
Place a piece of clean white paper on a hard surface, such as the floor. Rub the sole of the shoe against the white piece of paper with force but do not tear the paper. Look for a scuff mark on the paper. If you see a scuff mark, you do not have non-marking shoes.
Write with the heel of the shoe at the sole on another piece of plain white paper. Drag your foot with the heel across the paper and examine the paper for a marking. If you do not see a mark, you have non-marking soles. Although shoes with black soles are more likely to leave marks than those with light soles, non-marking black-soled shoes are available.