Your answer to No. 5 is "very spongy". The description says "high density". To me, high density means very firm. This is what I need. Please clarify.
739787
The foam is firm, but has a "sink into it" quality in my opinion. I used it as deck seating cushions, and just used it replace a bench cushion. It is very comfortable for seating, has just enough give.
71105
It is nicely dense. I have a king bed made up of 2 twins together and bought this to put on top. You cannot tell there are 2 beds and it is heavenly to sleep on. So much better than a plain mattress. Conforms to your body nicely but returns to original shape quickly. I cannot see a reason to buy a thicker one.
887759
This is 3" thick, and I thought of medium support. It went on top of a very firm mattress and made it feel like a nice memory foam mattress. I have two Tempurpedic beds. This was for my daughter's apartment. Made an uncomfortable bed feel awesome. So, I would say medium-soft density.
1072321
I don't know the density. It is fairly firm. However, I've stopped using it because of the horrible smell that would not go away.
654518
No, not particularly firm. It is NOT like TempurPedic...that is, you almost feel like you are enveloped in it.
203590
It has three different layers of foam. I don't remember if it even had the density but it is a wonderfully firm and comfortable mattress.We use it in our RV. I have the double and my sister has the king and she likes hers equally well.
563231
I would say more on the dense side although when I did what was essentially a spoom (made with an Italian meringe), it did come up a bit more fluffy. Have only used a few times but am impressed. Good luck.
1072323
I think the foam is fairly dense. I don't sink in too far; it does not become hammock like. Nor is it so firm that it is like sleeping on a board. We use it on a futon (extra bed) with a metal frame, and you cannot feel the metal bar of the frame when lying down. We use it to lie on, not sit, and for that purpose it is great.
28321
It is very cushy and thick. I would compare it to the "pillow top" of an expensive mattress. It is NOT like a foam mattress topper. It is luxurious!
804874
I was not impressed with the foam density of this cushion. I'm 210lbs and I just sank down to the hard board. Used it for a while but always with another cushion. Much happier with the Hermell Products Hip Cushion, 6-Inch. Good dense foam that does not allow me to sink but is also giving enough to be comfortable while seated for long periods. It does keep you raised which is great if you have longer legs.
1085898
As far as I know it's single density throughout...but I've been wrong once before. We replaced our 'custom' inner spring with this and whatever the density, it is by far the most comfortable mattress we've had so far, in fact we passed on our friend's guest room bed to sleep in our coach parked on the street in front of their house. Be sure to give it a full 72 hrs to expand before you sleep on it.
839363
It is very dense. My mother has a top-of-the-line Tempurpedic bed and this mattress topper feels about as dense. It's on the bed in our guest room and the two people who have slept on it really liked it. If you need a firm sleeping surface, I would definitely recommend it.
1278565
This was purchased as a gift and I didn't notice the density. I can only say the recipient has loved her seat pillow. Sorry I can't be more specific.
947354
I would say this is of medium density. For me it's perfect because it has a bit of give so it feels sooooo comfy, but it has enough firmness that it doesn't let you completely sink into it and it does have some support. My husband prefers a firmer mattress, thus a firmer topper than this one. Hope this helps!
1554205
Sorry, I checked the tags and didn't see a density rating. It is kind of squishy, but have found it to be very comfortable and worth the price.
632363
It is similar to a semi-soft dense foam when dry. Not crumbly. More like firm rubbery spongy. It does not fully "harden" like some foams do (probably a built-in safety feature to keep it from over-expanding and busting things like some of the original "expanding foams" did). Does not have any real stand-alone structural strength any more than styrofoam let's say, but will fill gaps nicely. If you were using it "sandwiched" between two sheets of plywood it would add some structural strength I should think. You may have to trim it around the edges with a razer blade or something similar after it expands and drys. Keep in mind that IT DOES !EXPAND! Your question did not give me a complete visual as to what you are trying to do/accomplish so this is the best answer I can come up with. Sorry.
64190
I didn't check the actual density but it feels pretty dense to me, three inches of high quality memory foam, can't go wrong!