An Old Master is a term for a European painter of skill who worked before about 1800, or a painting by such a painter. An Old master Painting is an original painting (for example an engraving or etching) made by an artist in the same period. Likewise an Old master drawing.
In theory an Old Master should be an artist who was fully trained, was a Master of his local artists' guild, and worked independently, but in practice paintings considered to be produced by pupils or workshops will be included in the term. Therefore, beyond a certain level of competence, date rather than quality is the criterion for using the term.
In the eighteenth and nineteenth century the term often had a starting date of perhaps 1450 or 1470; paintings made before that were "primitives"; but this distinction is no longer made. The original OED from the beginning of the 20th century, defines the term as "a 'master' who lived before the period accounted 'modern', chiefly applied to painters from the 13th to the 16th or 17th century." Rather surprisingly, the first quotation they give is from a popular encyclopedia of 1840: "As a painter of animals, Edwin Landseer
far surpasses any of the old masters".
We can recreate any kinds of old master painting reproductions by hand on
canvas.