UNFINISHED
SIZE VS
FINISHED SIZE
Here’sa reminderof themeaningof
‘unfinished’and‘finished’whenit comes
to sizes(seeFig 4 ). Theunfinishedsize
of a unitor blockis thesizethatincludes
the¼inseamallowanceallround(i.e.
½inextrain total).Thefinishedsizeis
thesizeminusthe¼inseamallowance;
thatis,thesizetheblockis onceit is
completelysewnintoa quiltor project.So,
an8infinishedblockis 8½inunfinished.Fig 4 UnfinishedmeasurementsvsfinishedFig 3 Diagonalmeasurement67ESSENTIALGUIDE lon-pointsettings
Joinusatwww.todaysquilter.com
DIAGONAL MEASUREMENT
The diagonal of a square is the line stretching from one corner of the square to the
opposite corner (see Fig 3). You could measure the actual block, but this isn’t always
the best or most accurate way (and you may not have made the block yet), so it’s best
to use a simple maths formula, as follows.
Diagonal = size of finished block x 1.414
For example, a 6in finished block will have a diagonal measurement of 8.48in
(6in x 1.414). Round this up to the nearest ⅛in and it becomes 8.5in (8½in).
For example, an 8in finished block will have a diagonal measurement of
11.3in (8in x 1.414). Round this up to the nearest ⅛in and it becomes 11.375in
(11⅜in). It’s also important to be aware of the difference between finished size
and unfinished size – see box and Fig 4, right.
WHY 1.414?
If you’re curious as to where the number
1.414 comes from, here’s the explanation.
In pure maths terms, the diagonal
measurement of a square is calculated by
multiplying the length of one side of the
square by the root of 2 (√2). If you press
the number 2 into a calculator and then
press the square root sign (√), you will
get 1.4142135 – which for our purposes
can be rounded down to 1.414.Setting triangles and corner
triangles were used in this sample to set the Four-Patch blocks
on point. However, setting and corner triangles are not just different
sizes but are cut differently − see Fabric Grain for the explanationDiagonal measurementSide measurementFinishedsizeUnfinished sizeSeam allowance