That's actually a sprayable polyester... I'll see if I can dig up some info.   

http://www.dupontpc.com.au/standox/stx-ep-primer-surfacer

This stuff dries like liquid steel reducing chance of sinkback and mapping of repairs underneath.Alternatively a quality spray polyester
for supreme filling and levelling can also be used.The Standox Polyester is very good and sands nice and easily.Definitely a step to be
performed if you want your vehicle panels nice n straight.I use Standox day to day so am slightly biased,however it depends on the operator
and budget too...how long is a piece of string as they say..good luck with your choice and remember you get what you pay for.Short cuts
in my industry can easily bcome LONG CUTS..Results like this Falcon are possible with hours of blocking invested..enjoy..

Hey Kevin,as a new bodyshop we really wanted to have a really honest attempt at showcasing our talents on our friends 1971 Ford Falcon GT.
Well,I was very proud at the Supernats car festival here in Sydney when we scooped=
Best Standard Paint
Best Muscle Car
Best Presented
Naturally our promo girls helped a lot,but the body and paint had no orange peel.It was absolutely flat as a sheet of glass in a C.O.B Brambles Red.(factory original colour).
The stripes laid down the side were painted on the car,originally they were vinyl decals.Every single component was installed brand new and with utmost care as not to damage
the finish.This car had 1200 hrs invested from start to finish from my crew of 10 dedicated tradespeople.Of course,a car like this cannot be possible without a consenting owner.
I will go through my archives and start my own build thread.
Sorry for hi-jacking this thread.If you want to move it elsewhere or delete it totally I understand..
Many thanks guys..especially you Kevin.Cheers Nick..Detroit Custom Bodyworks
<a href="http://www.youtube.com/v/CL3tmbnimWM" target="_blank">http://www.youtube.com/v/CL3tmbnimWM</a> (External Embedding Disabled)

Just another gratuitous reflection shot..