To decrease wave action in waterbed bladders, fibre floatation sheets or baffles are used inside the waterbed bladder to dampen this wave action. With more fibre sheets used the more wave reducing the waterbed bladder became. The overall thickness is what counts.
Originally bench mark was 500gram per square meter fibre and the general waterbed term, " one layer ", "two layer", "three layer" .......... was used.
Soft is a bladder that has no baffles
Medium is a 2 layer
Firm is a 3 layer
Extra firm is a 4 layer
Hard is a 5 layer
In waterbeds the general term "Layers" were used to gauge wave reducing stability.
However different layer thicknesses or weights came into the market. Now there are 300gram, 450gram, 475gram and 500gram layers in the market place.
As accumulative layer thickness gauges wave reducing performance, some manufacturers decided to reduce the layer thickness to less than 500gram/sqm So when customers ordered a 5 layer for example they could get;
5 layers x 500gram = Total Effective Performance of 2500
5 layers x 300gram = Total Effective Performance of 1500
5 Layers x 450gram = Total Effective Performance of 2250
As you can see the 300gram by 5 Layer will not have the same wave reducing ability as the 500gram by 5 Layer.
Please note that on this site each Level is 500grams. The reason we use levels is the fact that we use both 1000gram and 500gram Layers. So when we produce a 4 Layer x 500gram, we use 2 Layers x 1000grams. The layers are then stronger and stay intact longer.
We also use full sheet floatation rather than bar floatation to prevent sagging.