Block Construction
Definitions:
Shape
An individual piece with a distinct outline such as a triangle, square, rectangle, parallelogram, rhombus, pentagon, hexagon, octagon, and many more.
Pieced Unit
Two or more shapes sewn into a sewable shape, usually a square, rectangle, or triangle.
Block
Multiple shapes or pieced units sewn into a specific pattern or geometric design.
Seam Allowance
The amount of fabric that is added to the perimeter of a shape to allow for a strong seam. The universal standard for quilting is 1/4 inch.
Sectional Block Construction
A sectional-type block is divided into multiple sections to make assembly easy. Each section may include just one shape or multiple shapes as a pieced units. The pieced units are assembled first. Next, the sections are sewn together into rows. Lastly, the rows are sewn together to make the block.
The smallest unit (marked with an S) is the smallest section in the block. This will determine the ideal block size for that block. For the ease of cutting, the smallest unit needs to be a reasonable size that is not too small for your abilities and is a round number that is easily cut. In this example, all three blocks are divided into 9 units: squares, square pieced units, and rectangle pieced units. The recommended block sizes are different for each block.
Once you know the size of the smallest unit and have determined your block size, list shapes by shape name, width, and height.
Concentric Construction
Blocks constructed from the center outward uses the method of concentric construction. Sometimes the center starts as a unit but then individual shapes are added in a concentric manner.
