We explore two oil mediums, Artists' Painting Medium and Blending and Glazing Medium, examining the properties that make them suitable for certain purposes. For example, Artists' Painting Medium reduces viscosity and improves the flow of paint, whilst slowing drying time. This makes it especially useful for creating smooth, gradated colour, as well as glazing. Blending and Glazing Medium is similar, but it has a lighter body, and is the best choice when painting transparent layers of colour, blending colours and staining. It will leave you with a smooth, even surface with minimal brush stroke retention. It is important to consider the results you would like to achieve when choosing a medium, subtle differences can have a remarkable impact.