I Learned this trick from others on Dental Town. Passing it on.
Matrix within a matrix
Struggled to get Greater Curve band to go beyond the distal margin. Placed a rounded cut band fragment within the matrix past the margin. Look closely and you can see the piece of stainless within the confines of the GC matrix.
The band fragment was cut from the middle portion of the GC band.
Tooth restored with Activa. The band fragment also kept the Activa from extending too far distally. This made shaping the distal simpler. There was less bulk to cut back.