The two sketches were done with an altered felt tip marker.
By altered it is meant that three incisions through the wide felt tip and toward the barrel were made with a utility knife. This generated the triple line brush type look.
Take the amount of lines you see in parts of the sketches and divide by 3. Those are the number of strokes that produced them.
The sketches have been taken a step further:
1. Photographed in black and white.
2. Developed over 8×10 negative film which means that what was black on the paper became transparent and what was white became black.
3. White and red paper, as well as copper simulated film were applied to the back of the negative film for color.
The technique allows a single as well as multiple colors or even a texture to be used in back of the film.
If the negative film of the swamp had red paper in the back, because of the luster of the film, it would look like red ink.
One can easily take a Flair felt tip pen and give it a chisel point either by using a utility knife or a pair of scissors.
One can also alter the felt tips in other creative ways, even getting a spongy effect when they are way too butchered.
Some chisel pointed felt tip pens are out there for the purchase but the methods above can customize to suit needy situations and will not be found in the school supplies section.
If nothing else we could say “I did it my way”.