Making a flat thin pickup??

[Greg Bement]

My current build is going to need a thin 6 string pickup.  I'm wondering if anyone here has made their own pickup.. My last build I use piezo pickups but looking for a little better sound without spending big bucks.  The total depth I have to work with is 7/8",  I'm thinking a max thickness of 1/4".  Need some advice.  thanks