How to design your own quilt block

Start with a grid

Almost every pieced block is drawn on a grid of equal squares. The grid gives the block its family name: a four-patch is two squares by two, a nine-patch three by three, and so on up to five, six, seven and more. Each square of the grid is filled with a simple unit, and the units together make the design.

Look at any block you like and find its grid: count the squares along one edge where the seams line up. That’s the quickest way to learn how blocks are built.

The units that fill it

A small set of units makes most blocks. Learn to see them and you can draw, and sew, nearly anything.

Each has its own cut sizes: half-square triangles, quarter-square triangles, flying geese and snowball corners.

Draw your block

1. Choose a grid. On graph paper, draw a square and divide it into your grid, so each grid square is a whole number of the paper’s boxes. A nine-patch is a good first choice.

2. Fill each square with a unit. Draw diagonals for triangles, a line across the middle for rectangles. Keep every line running corner to corner or edge to edge of a grid square: that’s what keeps it easy to sew.

3. Use symmetry. Draw one quarter, then turn it to fill the other three, or mirror it. Most traditional blocks are made this way, and it’s why they look balanced.

4. Shade it by value, in pencil first: dark, medium and light. If the design shows in pencil, it will show in fabric. See Value and contrast.

5. Check it can be sewn in straight seams. You should be able to sew the units into rows, and the rows together, without stopping in a corner. If you can’t, the block needs a set-in seam (see Y-seams), or a line moved.

Pick a size the grid divides

Choose a finished size that your grid divides into whole eighths of an inch, the finest line on a quilting ruler. A nine-patch grid suits a 6″, 9″ or 12″ block; a 5 × 5 grid only a 10″. A dash means the squares fall between the lines of your ruler.

Then add the seam allowances when you cut each piece. Finished vs unfinished size explains how.

See it repeated

A block is only half the design: the other half is what happens when it repeats. Turn the same half-square triangle four ways, and the quilt makes pinwheels where none were drawn.

Draw four or nine of your blocks side by side before you settle on it. New shapes often appear where blocks meet; some are happy accidents, and some you’ll want to change. Quilt layouts explained shows how the setting changes it too.