Cut the side of the tile to finish making the shadow line.
Best way to cut drop ceiling tiles with a reveal.
Transfer those measurements to a ceiling tile and draw an outline of the cut on the front of the tile.
Measure the location of holes required in the tiles such as those for lighting or air vents.
With the tile cut to width i then make the shoulder or horizontal cut for the ceiling tile reveal.
A nice sharp blade that holds an edge is key here.
Pull the straight edge back about 1 2 inch and cut the vertical portion of the tile reveal.