On the lithos I have done, i have just made a simple box for them.
.75 thick stock approx 2" wide.
cut a 1/8" channel aprox 1/4" back from the front side, and a 1/4" wide x 1/4" deep rabbet along the back edge.
Measured the sided and cut the strip to length with mitered corners. Installed the litho in the channel then glued and clamped the frame together.
Measured and cut 2 led strips to fit into the top and bottom of the frame, wired them up and then hot glued them into position.
set a piece of 1/4" thick hardboard into the back and called it good. In the backerboard, I have also cut a keyhole into the top that way the frame can either be placed on a table or hung on a wall.
STGC(SW/AW) M. Wenman USN Ret.
1982 - 2005