The majority of my works are acrylic paint and/or ink. I use Professional Artist quality paints with high lightfastness so they won't fade or yellow over time.
I use archival quality lightfast inks; india ink, acrylic ink, gel pens, paint pens.
I also make pieces using Pencil, graphite, charcoal, watercolour.
I do not use oil paints.
n.b. I have used more unusual materials before (make-up foundation, coffee, tea, etc.. for different projects) and am happy to discuss the use of irregular materials for your piece. Important things to take into consideration are the archival qualities of the materials used. Few people want to commission artwork that will change color, disappear, or biodegrade while they're hanging in their house.