Hi Jill71rdh
Softness and thickness are related and work together. All else the same, a thicker mattress will “act” softer for most people. In your current configuration with the 3" soft Talalay comfort layer, it is possible that you are feeling through and bottoming out to the firm support layer below. By adding 2" to the existing 3" you will have 5" of foam to “travel” through before feeling the firmer layer below so it will isolate you a little more from the firmness of the layer below.
Opening the cover and testing your mattress without it will also help determine which type of firmness you are experiencing. This is because there are several “species” or types of soft and firm … as the same words are used to describe all of them even though they mean different things and different people may be more sensitive to one or the other. There is the soft/firm that describes the surface “feel” of a mattress or the “hand feel”. There is the soft/firm that describes the upper layers and the pressure relieving ability of the mattress and how well it forms a pressure relieving cradle that re-distributes weight. There is the soft/firm that describes the firmness of the support layers and how far the heavier parts of the body sink down. Finally, there is the soft/firm that describes the more subjective overall feel of the mattress. Some people use the same words to describe very different perceptions or the “species” of softness and firmness that they are most sensitive to. All of them are different. So when people talk about the softness or firmness of a mattress … it’s important to know “which” softness or firmness they are talking about (hand feel, pressure relieving softness/firmness, deep support softness/firmness, or overall perception) because the “overall impression” is not really specific enough to know what is happening when you lie on a mattress.
If the cover is taut then it will subtract from the overall plushness, if it is a little looser or stretch knit then it will feel a little plusher. Layers closest to your skin can have the most dramatic impact upon your comfort. Depending upon the thickness and the weave and the blending of other materials, a cover can be stiff or barely noticeable. Quilting wool into the covering will give it a bit more rigidity and some extra comfort, but it will tend to be on the slightly firmer end of the spectrum, especially as time goes on, as wool does tend to compress. This would, of course, depend upon the amount of wool used and how tightly it is quilted to the material. I wouldn’t try to fit 5" of foam into a cover that is designed for 3". You would need to purchase either a stand-alone topper, which means it is already within its own cover…or … you can order a bare latex layer and replace your existing mattress cover with a thicker one that can accommodate the additional layer.
This is correct and while natural latex would be slightly more “springy or buoyant” and more “supportive” the blended (or synthetic) would generally feel a little softer and be slightly more pressure relieving and would allow for slightly more sinking in and cradling, but again as described above the cover will also influence the overall feel.
Phoenix