During Operation Night Watch, Rembrandt’s masterpiece can be seen in the gallery without its frame. This way we can study the edges – usually referred to as tacking edges – of the painting.
Because The Night Watch has been reduced in size along all four sides, the original tacking edges are no longer preserved. The plain canvas we now see is actually part of the lining canvas that was applied in 1975. During a lining an extra canvas is ‘adhered’ to the reverse of the original canvas, in this case with a mixture of molten beeswax and resin. In total the painting was lined three times with a mixture of wax-resin (1851, 1945, 1975) and at least once using glue-paste prior to 1851.
In the picture, the lining canvas from 1975 is shown in red, the tacking edges in blue and the original painting in white.