I have been decorating frames that have languished in the studio. Acrylic pens of different sizes. Classic traditional/architectural designs. Working now on the little oil paintings that will fill them.
LIQUITEX paint markers with Winsor Newton permanent pigment markers for detail. The later are meant to be floated on a non-porous surface, which the Liq.' pens create on paper.
The bottom image is on mounted watercolor paper. The suns are on Raymar boards; 6 x 8 inches.