What should I look for in a tummy time play mat?

When selecting a play mat for a 4–5 month old to practice tummy time and crawling, look for mats that are at least 10mm thick. A thicker mat provides better cushioning for impact and stays in place more effectively than thinner options, making it sturdier for a developing baby. Waterproof, reversible options are often preferred for easy cleaning and long-term utility as the baby grows.