Back of the painting and frame before intervention. 

Contexts in source publication

Context 1

... painted panel measures 94 x 124 cm and it is made of four oak planks cut radially (Figure 4). They have solid and relatively straight grain ori- ented in a horizontal direction. The oak was the most common support used by painters of the Northern school. The planks vary in width and are 22-27.5 cm wide which was common in the Northern countries [5]. The thickness of the planks is 7-10 mm. No knots or defects nor cut-marks were found on the panel which suggests that the panel's planks were carefully sourced, and after assembly their surface was planed until completely smooth. The assembly of the planks was achieved by hori- zontal butt-joining and accurate planing of the faces to be united and then making incisions to improve the bond of the natural skin glue what appears to correspond to the traditional prepara- tion found in Cennino Cennini's Treatise on Painting [6]. To assure an accurate alignment, dowels made of hardwood were used ( Figures 5, 6). A visual examination of the joins faces revealed three carved housings at regular intervals inside the thickness of each plank. The floating dowels were inserted in these housings without glue with the grain across to that of the support in order to maintain the position of the planks until the glue applied on the edges had hardened. This method was a standard for joining the planks for large panels. The larger panels of standard size (75 x 110 cm) made of three planks would have had three dowels in each join. As panels produced in the northern countries became thinner toward the end of the 16 th century (8-30 mm thick) dowels replaced the butterfly keys for stabilizing and aligning the joins during gluing [5, p. 155]. There- fore, the butterfly keys on the back of the panel painting "The Death of Sapphira" can be a later addition. Probably early in its history the original butt joins broke and the oak butterfly keys were inserted into the boards as deep as one-half of the board thickness, with their grain running crosswise to the board's grain, to hold the adja- cent boards tightly together ( Figure 7). Then, at the end of 20 th century, an attempt was made to stabilize the panel by gluing two oak crossbeams, each 80 mm wide. They were glued on the reverse of the panel across the grain of the boards ( Figure 4). The role of the crossbeams was to stabilize and hold the four planks together as some but- terfly keys and joins had become loose. Unfortu- nately, they had a negative effect because they caused an extreme concave warp of the panel's ...

Context 2

... painted panel measures 94 x 124 cm and it is made of four oak planks cut radially (Figure 4). They have solid and relatively straight grain ori- ented in a horizontal direction. The oak was the most common support used by painters of the Northern school. The planks vary in width and are 22-27.5 cm wide which was common in the Northern countries [5]. The thickness of the planks is 7-10 mm. No knots or defects nor cut-marks were found on the panel which suggests that the panel's planks were carefully sourced, and after assembly their surface was planed until completely smooth. The assembly of the planks was achieved by hori- zontal butt-joining and accurate planing of the faces to be united and then making incisions to improve the bond of the natural skin glue what appears to correspond to the traditional prepara- tion found in Cennino Cennini's Treatise on Painting [6]. To assure an accurate alignment, dowels made of hardwood were used ( Figures 5, 6). A visual examination of the joins faces revealed three carved housings at regular intervals inside the thickness of each plank. The floating dowels were inserted in these housings without glue with the grain across to that of the support in order to maintain the position of the planks until the glue applied on the edges had hardened. This method was a standard for joining the planks for large panels. The larger panels of standard size (75 x 110 cm) made of three planks would have had three dowels in each join. As panels produced in the northern countries became thinner toward the end of the 16 th century (8-30 mm thick) dowels replaced the butterfly keys for stabilizing and aligning the joins during gluing [5, p. 155]. There- fore, the butterfly keys on the back of the panel painting "The Death of Sapphira" can be a later addition. Probably early in its history the original butt joins broke and the oak butterfly keys were inserted into the boards as deep as one-half of the board thickness, with their grain running crosswise to the board's grain, to hold the adja- cent boards tightly together ( Figure 7). Then, at the end of 20 th century, an attempt was made to stabilize the panel by gluing two oak crossbeams, each 80 mm wide. They were glued on the reverse of the panel across the grain of the boards ( Figure 4). The role of the crossbeams was to stabilize and hold the four planks together as some but- terfly keys and joins had become loose. Unfortu- nately, they had a negative effect because they caused an extreme concave warp of the panel's ...