To minimize wear of the graphics and finish, I put all of the coloring on the underside of the clear plastic panel.
Tape your track diagram on the underside. This is somewhat tricky since you will be taping in reverse of the schematic. If you have a drawing of the plan in the correct size for the panel you're using, you can have it photocopied in reverse image. Then you can lay this on the workbench, position and hold (tape) the plastic panel over the diagram, and apply your tape.
Fancy colored tape isn't necessary. Blue painter (or Frog Tape...new kid on the block brand) in the width of choice will actually be better to work with (MHO, of course). Just be sure to burnish the tape edges down to avoid paint bleed.
Drill all of your holes for lights and switches. I've found that a sharp drill bit, run at a slow speed and slow feed, will minimize chipping. Also, drill through to a scrap support board...old piece of plywood, etc...backing up the material will support the surface at the moment of breakthrough. Try your drilling on a scrap piece first, however, to get the technique correct. You may, for instance, prefer to drill your holes from the first surface (outside) direction so any small amount of chipping would be on the inside (taped) surface.
Now you're ready to paint. Spray the entire taped surface the basic field color of your panel. I used flat black. I've seen greens and blues used on some layouts....it's really your preference. It should be a color that will contrast well with your layout line color applied in the next step so that the schematic will 'pop' out.
Let me emphasize one thing about this basic field color step. YOU WANT TO BE SURE IT HAS BEEN APPLIED ADEQUATELY TO ALLOW NO LIGHT...OR SUBSEQUENT LIGHTER PAINT COLOR...TO SHOW THROUGH!!! I learned this the hard way...but only once! If you spray your color (best technique) it will seem to be adequate after the first coat. BUT, if you hold it up to the light, you will be surprised how thinly covered it may actually be. This is not good for the next step. If you apply a white or yellow to achieve the schematic pattern, the lighter color will show through...in a funky, junky sort of way...the basic field color. THEREFORE, take time to apply several light coats of the field color, checking the opacity.
When you're satisfied with the field color/opacity quality, carefully pull the schematic tape. Pull it slowly and in a direction nearly parallel to the panel. Do not pull masking tape at a 90-degree or steep angle.
Now spray the schematic color of your choice. I used a bright yellow. Many use white, red, et al. My comment on this step is to spray the entire panel surface...covering all of the field paint, not just the schematic area. My reason is that regardless of your care in ensuring opacity of the field paint, the addition of the lighter schematic paint may yet 'lighten' the field color when viewed through the panel. Ergo, you don't want a 'blob' of this lightened effect as a halo in the center of your panel. Applying the schematic paint evenly over all of the field paint will give a more uniform appearance.
From here on out...mounting switches, lights, attaching to the control panel frame, etc....just take care to avoid scratches through the painted surface. I had a large old bath towel on my workbench to help in this regard while working with the panel.
FWIW, that was my technique.
Lots of techniques to choose from, though.
KD
