Colour portraits allow for more emotional resonance than black and white pictures. Pastel allows very nice gradients to be produced, but the price is a lack of fine detail. Biro can provide lots of detail but the pen strokes are inevitably visible which reduces the smoothness of any gradients. Watercolour can provide spontaneity for backgrounds and underpaintings but I usually add pastel to gain greater control. Commission portraits are available through Etsy.com. There is a link on the "Commissions" page. A3 size (42cm x 29.7cm) or larger is recommended for pastel pictures, while biro can work down to a size of A5 (21cm x 14.8cm). Multiple people can be included in a portrait at no extra cost but the smaller each face becomes, the less detail can be achieved. Biro is particularly suited to pet portraits to give an impression of fur.