We both are working on 1/4" wood panels, these are the charcoal drawings, mine (left) is 11x15, Tom (right) is 12x16.

On the charcoal drawing I made an acrylic line painting, then moist cleaned the panel of chalk, or in this case, the charcoal.
Tom is painting in oils. My painting is acrylic.
I'm the one using a stick for and easel.

This are the paintings after the first 6 hours. Tom Booth is finished!

My painting after the second day.

The third day, eighteen hours later.
Now I will give it a final "varnish" coating using a polyurethane water based finish.
The best out now is by Deft, called "Millennium".

Mistake

 

Corrected

Now the perspective is correct with all the angles meeting on the horizon line.