16th century joiner's marks

I am looking at a 16th century painting on an oak panel consisting
of six horizontal planks. One of the planks has some joiner's marks
cut into it, which don't correspond to the adjacent plank. Four of
the strokes are verticals but there is also a triangular mark
pointing right. Does anyone have any information which could help to
interpret these marks or explain their significance?

Kate Lowry
Paintings Conservator
National Museum of Wales, Cardiff


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                  Conservation DistList Instance 21:28
                 Distributed: Friday, October 26, 2007
                       Message Id: cdl-21-28-022
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