Run your hand across the top surface of the mattress. It should be completely flat, with no bumps, dips or bunched-up bits. While producers such as The Little Green Sheep (see their Twist cot bed mattress above) are admirably transparent, the consumer organisation Which? believes that others play fast and loose with terminology. They say: "Manufacturers can use the terms ‘natural’ and ‘organic’ on products without needing any sort of certification. There are legal requirements for the labelling of organic foods, but not these products.” This does make them more expensive, however, so if you’re going for a budget model and it doesn’t have a removable cover, it would be well worth buying a separate protective cover for it. Eco-credentials

There’s no getting around it. Cot mattresses aren’t a buy for life, so lots will end up in landfill. But if you’re fully committed to a green-friendly solution, be careful to read the small print. Spring-interior mattresses are mini versions of a typical adult mattresses and coir and Purflo mattresses are part of a subset of innovative, premium-priced ‘green’ products. An effective cot mattress is about so much more than a good night’s sleep. Like choosing the best baby monitor in your price range, it's about safety and peace of mind. As well as making their cot bed a firm and supportive place for your baby to snooze, the best cot mattresses will also ensure snuffle-free sleep for children with allergies, and help keep them cosy when it’s cold and cool when it’s hot. Like the Snüz Surface Duo Cot Mattress, above, this mattress has two surfaces: the firmer baby surface and, on the other side, a softer surface for when your baby grows into a toddler. The main difference is that this mattress is a cot bed model only, which we think is a more natural fit for this type of baby-to-toddler option. It also has a waterproof cover that's removable and washable, like the Snüz - a very practical addition. Truthfully, the look of a baby cot mattress should always be secondary to safety. There’s no getting around it. You might like ribbons and frou frou around your four-poster bed, but where a child sleeps should be kept simple and unfussy.

How do I test that my cot mattress is firm enough?

With features including perspiration control and temperature regulating additives, baby will be cool and comfortable all night long. With a water repellent and a wipe-clean inner, you can keep your mattress clean and protected against nighttime incidents. Great peace of mind. Before we recommend new products, we always ask our trusted Mumsnet users, of which there are more than 7 million each month. That’s a lot of honest, impartial advice. Expert guidance

If you’re going for a more premium brand, you might want to think about its longevity. Some mattresses will last a child up to four years of age, such as the Snüz Surface Duo Cot Mattress and the Silver Cross True Fit Superior Cot Bed Mattress that we’ve featured in our round-up, so suddenly a slightly hefty price tag doesn’t seem so bad. Are secondhand cot mattresses safe? But essentially, if you want to give the mattress a thorough clean, first remove the cover, wash it according to the instructions and ensure it is thoroughly dry. Some mattresses can be washed themselves, but most are wipe-clean at best. At Mamas & Papas, we understand the importance of sleep for your little one. In the first two years of their life, a baby will sleep for thirteen months, helping to develop their cognitive skills and nervous system, so a good night's sleep is important. Mamas & Papas Mattresses are designed to support a good night's sleep, so both your little one and you can enjoy a silent night.

Why you should trust us

Whether you’re buying a cot mattress, a travel cot mattress or a cot bed mattress, you must make sure that, as a minimum, it’s protected by a waterproof cover to help keep the mattress clean and dry. The mattress has two different surfaces (one on either side, obviously): a slightly firmer surface for babies to give them the safe support they need, and a softer side for toddlers. To change between the two sides, you just zip off the removable cover and turn the mattress around inside it. Some have a special surface for sleeping on that might be water-repellent or hypoallergenic, for example, so that needs to stay on top. Others, such as the Snüz Surface Duo Cot Mattress and the Silver Cross True Fit Superior Cot Bed Mattress above, have a ‘baby’ side and a ‘toddler’ side with differing levels of firmness. And because purchasing a new mattress is crucial for a supportive and protective night's sleep, we'll always be here to help your growing family settle into their sleep routine. Their advice, and ours, is to scrutinise the small print of product specs to ensure that materials used are truly what they purport to be. Budget

There are many elements to consider when choosing the best cot mattress: Safety – what’s the safest cot mattress? It’s a good idea to rotate your baby’s mattress 180 degrees every month or so, just so that it wears evenly. Most mattresses these days don’t flip. Coil spring cot mattress – open coil springs surrounded by foam and fillings. Tends to be sturdier than a typical foam mattress.There are many types of cot and cot bed mattresses on the market, and they come with many different styles and features. Broadly speaking, here the five main types of cot mattress and cot bed mattresses: verifyErrors }}{{ message }}{{ /verifyErrors }}{{ You should also ensure that the mattress fits well, with no gaps between the mattress and the cot, and that the mattress itself is both clean and dry. What size should a cot mattress be? For support, your choice of cot mattress should be no thinner than 8cm. However, a minimum of 10cm is what most experts, including Which?, recommend.