You will be using that line as a guide for placing the two strips of wood which will hold the drawer hardware.
Convert kitchen cabinet to trash pull out.
1 x 12 cut to 22 1 x 6 cut two pieces at 11 1 4 and two pieces at 20 1 2.
Measure up from the bottom of the cabinet sides and mark the height you ve just found the trash can height plus one inch with a pencil.
Attach them with two screws and two triangular cuts of 2x4s to form the door and base that the trash can would sit on.
Use a level to extend that line across the width of the inside of the cabinet wall.
Cut your lumber or have it cut for you at your home improvement store.
If you re making two pull out trash can cabinets one for trash and the other for recycling you ll need another 1 x 6 board and double the cuts.