Acrylics (brushed or air-brushed), oil paints, brushed-on pastel dust, and etching away the original finish paint with an x-acto knife are all common materials and methods for altering the appearance of a model. Coloured pencils, watercolour (pencil and paint), and even ink are sometimes used as well. The preference for sculpted or hair manes and tails goes in and out of vogue and can vary by region as well. Mohair is generally used, though some artists use glue-coated embroidery thread to great effect creating something between a sculpted and haired appearance.