"PVR" wrote in message
...
I want to butt joint two grain printed boards, one 11.5" wide, one 8" wide
and both 6' long. I'm thinking of using biscuits and water borne glue.


You don't say how thick, but given the way MDF or other fine-grain particle
boards swell and stay, I'd go dry biscuits for alignment, and something
other than a water-based glue or sparingly.

Better would be the reverse glue joint type of router bits, though if the
pattern is plastic imprint, you might want to check it on a scrap piece.
Continuous spline is easily enough done, and you could make it a bit deeper
than normal if the joint will be under any kind of stress.