LEGO Techniques - Embiggening Baseplates

A few weeks ago I showed my technique for trimming baseplates to size or creating new canon baseplates out of a damaged one (for you purists).  It occurred to me that sometimes you might need a bigger baseplate area that is available with standard parts (said the micro builder).  You could find instructions online for creating a LEGO table out of several standard baseplates.  Given that they are 10" to a side, a 20"x30" playspace would be fairly easy to put together.

So you've glued your baseplates down to your surface, making sure to use a good glue and making sure to not leave any gaps.  You go to build a monster and creep beyond the 32x32 stud size when suddenly-

"What the?  What's wrong with these?  Why won't my piece fit across two baseplates?  Stupid Danish engineering."

Au contraire my friend.  It seems you have no tolerance.  No, I'm not talking about your mental state of being so much as I am talking about the LEGO pieces themselves.  Most basic pieces have a 0.1mm tolerance on each side.  Baseplates seem to have a touch more.  When you line baseplates up and tack them down, you need to make sure there's at least a 0.2mm gap between them.  "Augh, how do I measure that!?"  Simples:

Just "stitch" your plates together before adhering them.

I'd love to do this to my truck, actually...