Here's another idea, but it might be expensive, especially compared to cardboard.
Go to a feed store, ranch, farm supply, whatever they have in your area (well, maybe
not in the Bronx). They have large, thick, heavy-duty mats for use in horse trailers,
stalls, whatever. Might be a good investment if you are going to spend a lot of time
under the beast on gravel.
Jerry

----- Original Message -----
From: "Jonathan Poole" <jfpoolio@GMAIL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Friday, April 29, 2005 3:48 PM
Subject: Working on Gravel

Unfortunately I have spent many hours working on VW's on a gravel
surface..  The job that you have to do won't actually be that bad
though,, at least you aren't pulling the tranny or replacing the cv
joints or something that keeps you on your back...

The only things that I have found is that:

you do want to use a plate of some kind to keep the jack from sinking

you need to be extremely careful with any small parts because you
could be stuck looking through gravel for hours for a dropped part.
(really)

Home Depot and Lowes type places have nice foam mats that you can lay
on,, the one that I use consists lightweight but stiff foam squares
that piece together like jigsaw puzzle pieces.  You can build a pad
for that is comfortable and that will help you find dropped parts..
This stuff is really cheap so you don't have to worry about getting it
oil soaked etc..

Jonathan Poole