Oil colors form a greasy layer and are therefore not suitable as a background for acrylic colors.
The firmer hair brushes are the most used for acrylic painting.
Hog-hair brushes can handle a lot of thick paint, but are too inaccurate in stroke for fine detail work. Also, with water, hog-hair brushes become a little less resistant.
Synthetic brushes (selected filament) are unaffected by water and are suitable for thick and heavily thinned paint as well as fine details.
Acrylic color brushes have a long handle so that you can keep a sufficient distance from the paint.
Mediums are used to change paint properties such as thickness, gloss, flow, drying time, transparency, and durability.
Many painters only use water with acrylics, but this doesn't always produce the best results. Mediums can be used to achieve better, longer lasting results with less paint.
Adding too much water can separate the paint pigment from the binder; the pigment is then unprotected in the paint and can bleed.