Acrylics applied with single 23" wide stiff bristle brush guided by cable or fixed swivel to provide light-catching grooves, with some exceptions eg. flag. More recently adding point of realism or two on horizontal base with colors drawn out by cable guided brush.
4th generation painter - most prolific by far was grandfather who managed steel mill as a day job. 25 years painting, NY oriented but based in CT. A complete unknown.