I
had some balsa (may be bass
wood)
wood sheets 1/16" x 3" x 24 inches long that were scored every 1/4 inch so you could make strips the width you needed. I used 1/2 inch strips. I marked them out for the size of the small squares and with scissors made notches half way thru the strips. Then by laying the strips running right to left with the notches up and the strips front to back with notches down to make a grid. The
wood on the perimeter was not notched. I then used a very small spot of glue on each joint ( I used shoe goo, love that stuff) once it was dry, just a few minutes I again
applied small dots of glue at regular intervals on the top of the grid and then turned it over onto the tray and held it down with a book until dry.
The sticker on the back of the sheets say MIDWEST micro cut select.
Norm