18th century naive portrait.

Small 18th century naive portrait. The original frame had lost all its moulding, but the unpainted area on the corners looked to me like oak leaves, so a walk to local oak tree and voila ... Back of canvas with board removed showing date marks - revealed now painting is on stretchers.

It's a painting of a composer holding a quill pen and lost in thought as he sits at his piano.

Stamp marks :

Canvas was taxed in the 18th century. As a consequence of legislation in 1784, a 'frame mark', associated with the duty payable on linen, was applied by the Excise to the back of canvases. It can provide useful information both as to the width and the length of the roll from which the canvas was cut. The mark took the form of a frame containing numbers and letters in compartments. Hence on Lemuel Abbott’s portrait of Viscount Bridport, 1785, the canvas width is given as 75 hundredths of a yard, i.e. 27 ins, the canvas length as 17 yards and the year indistinct, while on George Morland’s Inside of a Stable, exhibited in 1791 (Tate), the canvas width is given as 165 hundredths of a yard, i.e. 59.4 ins, the canvas length as 265 (apparently 26 ½ yards) and the year as 1790.

Detail from reverse of Lemuel Abbott’s Viscount Bridport, 1785 (National Portrait Gallery). 75, in the compartment at right, give the canvas roll width in hundredths of a yard, thus 27 ins (68.6 cm). To the left, 17 is the roll length in yards, thus 17 yards (15.55 metres). Further left, 2224 is a progressive control number. The illegible small numerals, turned sideways at extreme right, give the year duty was levied. At left, the mark is partly covered by the wooden stretcher. Above, the other way up, is the stamp of the canvas supplier, James Poole.

Further reading.