Platter mat ?

I am using a VPI hw19jr TT. I have been using it for about 2 years without a mat. I have been just running the bare platter with the LP clamped to it. Is there a need for a mat on this platter?
I didn't think so, but I have been looking at pics here with mats on the platter of the 19jr. Does this make sense?
VPI says that the acrylic composition in the platter acts as a mass-loaded "sink" that absorbs vibration from the LP caused by the stylus. However, many owners of the various HW-19 models (me included) have tried platter mats to see whether they improve the sound. Over the past 15 years, I've tried a half dozen or so different platter mats on my HW-19 Mk4 (with TNT platter, bearing, etc.), and eventually adopted VPI's cork platter mat. It seems to give the table a slightly more "live" quality, which works well in my system, and for the $10 cost (from VPI) it's certainly an inexpensive solution.
Wow, I own a HW-19 Mk3 and was about to post a similar question. Anyway, I run mine without a mat, though I do won a couple of different mats. I never noticed any sonic difference with or without the mat (I always remembered to adjust VTA) so I ditched it. Aside from sonic benefits/artifacts, does having the mat help protect the "other side" of the LP when it's playing?
I have tried several mats and did not care for any of them. Tweaks, as a general rule, are a real interesting phenomenon. I usually hear differences for sure, but SYNERGY in the system and components is really the key to the best sound I believe.

Wow, this reminds me of the Platter Matter. They were originally blue, then later ones were brown. I bought a brown one but never used it. Can't say how they improve the sound, but know they are slightly tacky so they grab the record, make it flatter and more stable. Some people swore by them - they were quite the rage in the analog world then.
I started out bare-platter on my early (Mk. 2) model TNT, went through a couple of clamps including the one from Black Diamond Racing, then discovered that the Ringmat, sans clamp, sounded better to me. I switched to a graphite Boston Audio Mat 1 since then and like it marginally better than the Ringmat (whether it's worth $195 is another question). Don't think I'll ever go back to a clamp, though. Dave