Vibration Isolation

About a year ago I purchased the blue and the natural cork color (different materials) from the same company that is in the opening post. They do work well, the company also offers a variety of sizes, for example, I have one that's 18" x 18" etc.
One word of caution seems like all of these types of isolation devices (rubber/cork/rubber) will leave black marks on your wooden platforms, that I have nor figured out how to remove.

It can be demonstrated fairly easily the best approach, generally speaking, to vibration isolation and resonance control is the deliberate and coordinated implementation of a combination of mass on spring type isolation and vibration damping for the top plate of the iso system. The art of isolation comes in when interfacing the component to the top plate and interfacing the iso system to the floor or rack, not to mention the choice of damping method and material for the top plate. This attack will address very low seismic vibration, acoustic vibration and “residual vibration” on the top plate that arises from several sources. If it was easy everyone could do it.

@lak   I believe that either "Goo Gone" or "Goof Off" should, with some elbow grease help you to get rid of the black marks.  

@hifiman5, thank you for the information. I'll give it a try :-)

I recently contacted Diversitech (email) and asked about the Durometer spec on the 2x2" EVA (blue center) pads. Hoping for a reply. FWIW - one of our senior members had recently opined that these will do nothing for audio as they are too hard. I am not voicing an opinion in that regard. I have both blue center EVA pads as well as the cork center pads. It would be helpful to know the Durometer value and relevant Shore scale as this will allow comparison to some products from Herbie’s Audio Lab (with which some of us are more familiar). If interested see also the chart at the link below.

https://www.smooth-on.com/page/durometer-shore-hardness-scale/