We have a lot of customers asking about how firm a medium or a firm mattress is. And to be honest, every mattress company has their own. The universal approach used is through two factors: a concept called Indentation Load Deflection (ILD) and Density.
Natural latex comes in different firmness levels such as Soft, Medium, Firm etc. Density or ILD is the way we measure the firmness of our mattress.
A material’s density is defined as its mass per unit volume. It is, essentially, a measurement of how tightly material is crammed together. Density of natural latex used in mattresses usually varies from around 60 kg/m3 to about 95 kg/m3. The higher the density is, the firmer the mattress will be. Zaanta Medium mattresses are 85kg/m3 and Firm mattresses are 90kg/m3.
Indentation Load Deflection measures how hard or soft the Natural Latex is. It is calculated by measuring how many pounds of pressure it takes to indent a four inch thick piece of Natural Latex foam by 25%. This test is done by applying the pressure across an area of 50 square inches. The amount of pressure required is then converted into a weight. The Indentation Load Deflection number you see on various mattresses is that weight. The greater the ILD, the firmer the natural latex will be. The ILD of natural latex commonly used for mattresses is between 20 ILD (very soft) – 45 ILD (very firm).
Apart from the Density and ILD, differences in the fabric used for the mattress encasement and how tight the encasement is made can also attribute towards the firm or soft feel of the mattress. If the cotton ticking is flexible, like a knit fabric or similar, the mattress likely will feel softer than if the mattress ticking is taut. Similarly, if the mattress encasement is tight, the mattress will feel firmer than if the encasement is slightly looser.
If you’re still not convinced, contact us to find out more, or if you’re in the area make a booking and visit the zaanta bedroom! Either way, its time to start #feelingZaanta!