finished size
the finished size dimensions are the measurements of the unit/block that one sees on a completed top (before quilting)
some of the factors that affect that size are:
-was the fabric washed before cutting it?
-cut size of the pieces
-how wide is the seam allowance
-thread used
-thickness of the fabric - one has to .allow for how much "take up" happens whenever there is a fold
-steam pressing of some unwashed fabrics can cause shrinkage
-uneven seam allowances
-pressing/ironing technique
if the " finished size" is critical for a particular project, do the "three strip" test to see if any adjustments are necessary.
making a test block is even better.
the 1/4 inch seam is an important factor for accuracy - but it is not the only one.
there are projects where consistency matters more than having a "perfect" 1/4 inch seam.
if/when doing string or crumb piecing, for me, it only has to lay flat and not pull apart.