No not necessarily. The tummy time pillows that come with the play mats are quire large and work best for older, bigger bubs (3-4 months and up) There are great water proof and/or wipeable mats which make for easy water play and clean up after spewy babies, my favourites are Rudie Nudie Designs (great for outdoor adventures too) or Grace and Maggie Play mats if these are in your budget.  It is all about creating a firm (but soft) surface for your little one - a quilted rug is fantastic too, rudie nudie tummy time is one of my favourite activity suggestion to build your little ones tolerance and enjoyment of tummy time - it just means a bit more washing and problem solving if its not waterproof.