Graph and Instructions for Canadian smocking using design " Bones"

Here is the graph for making cushions with design “Bones”. This design also consists of columns marked with diagonals separated by gaps. While drawing graph we have to keep in mind the last column should not be a gap.

Method of calculating material needed

If you see the reverse of the"'Bones " design we find formation of equilateral  triangles.
Let us consider that we smock 2 rows of squares having 2 squares in each row.We get an equilateral triangle ABC (See figure 2) whose sides are equal to the diagonal of the square which is used for smocking. Using this we can calculate the material needed for smocking for the required size of cushion.

Let us calculate the material needed for a cushion of size of the cushion 40 cm x 40 cm and size of the square of the graph used =2 cm Χ 2 cm
  (please refer the chart)
Base =Diagonal of the square of square of side 2 cm= 2.8 cm
Height will be 2.4 cm.   
Let us calculate the length
Every 2 rows we smock the length will become 2.8 cm
Or in other words, to get 2.8 cm of smocked we need 2 squares or 4 cm material.
To get 40 cm of the smocked material we need 40 Χ 2÷2.8 = 28.5 squares or 28 full squares.
Material needed for 28 squares is 28 Χ 2 cm=56 cm
Add 2 cm for the seams on both sides
Length of material needed = 56 cm+ 4 cm =60 cm
Let us check .If we smock 28 squares we get 14 Χ 2.8 cm = 39.2 cm
There is a deficit of 0. 8 cm .This can be made up by adding 1 cm more for the seams that is ½ cm extra on each side.
Length of the material will be 61 cm.
Let us calculate the width of the material needed.
Width of the smocked material is the height of the equilateral triangle.
In this case it will be 2.4 cm.
Every 2 squares or 4 cm we smock it will become 2.4 cm in width.
Or in other words to get 2.4 cm of the smocked material we need 2 squares or 4 cm of material.
To get 40 cm of smocked material we need (40 Χ 2) ÷ 2.4 = 33 squares.
Material needed for 33 squares =33 Χ 2 = 66 cm.
By adding 2 cm on each side it will become 66+ 4 = 70 cm.
If we smock 32 squares we will get 16 Χ 2.4 = 38.4 cm.
We get little more for the last line.
Material needed of width 70 cm.
So the material needed for making a cushion of size 40 cm Χ 40 cm in the design “Bones “ using a graph of 2 cm square = 70 cm X 61 cm
In this manner we can calculate the material needed for any size of cushion done using any size of squares.