Learn how to sew a 9 patch quilt block with this comprehensive guide to making and sewing nine patch quilt blocks. This guide will teach you what a nine patch block is, how to sew a nine patch quilt block, with scraps or square by square, how to strip piece a nine patch block, how correctly press a nine patch block, how to nest the seams, and how to square up a nine patch block.
You will also learn the formula to figure out what size squares to cut. I have made a hand PDF 9 patch block cutting chart as well as a hand pdf cheat cheat for piecing. Additionally I have provided some fun 9 patch block variations for inspiration.
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Table of Contents
What is a Nine Patch Block?
A nine patch block is one of the basic quilt blocks. It is a beginner friendly quilt block that joins nine smaller squares to become one larger block, usually resulting in a repeating pattern using light and dark squares. Although it can be composed of other blocks such as half square triangles and four patch blocks and does not necessarily form a repeating or symmetrical pattern.
Nine patch blocks are usually made with light and dark contrasting colors. Block A is sometimes known as a positive block, while reversing the placement of light and dark colors will make Block B or a negative 9 patch.
How to Sew a 9 Patch Block using squares or scraps.
To make a 9 patch block using single squares or scrap pieces follow the directions below. You will piece each row a square at a time and then join the rows together to form a 9 patch block.
Chain piecing can make the 9 patch block come together more quickly. Learn how to chain piece with this video and tips.
- . Using a 1/4" seam sew a dark square to the opposite sides of the white block. Make 2
- . Using a 1/4" seam sew a light square to the opposite sides of the color block.
- . Positve or A Block - Using a 1/4" seam sew a strip made in step 1 to the opposite sides of the strip made in step 2. Or alternatively make it with the opposite placement as shown in step 4.
- . Negative or B Block - Using a 1/4" seam sew a strip made in step 2 to the opposite sides of the strip made in step 1.
How to Strip Piece a 9 Patch Block
To strip piece a nine patch block you will start with several strips of fabric the height of the block you want to make. You will join the strips for form long rows of alternating colors. Once the rows are formed you will cut them into smaller strips and then join these strips together to form the nine patch block.
- . Using a 1/4" seam sew two dark strips to the opposite sides of the white strip.
- . Using a rotary cutter, cut the unit made in step 1 to the block width needed.
- . Using a 1/4" seam sew two light strips to the opposite sides of the color strip.
- . Using a rotary cutter, cut the unit made in step 3 to the block width needed.
- . Positve or A Block - Using a 1/4" seam sew a strip made in step 2 to the opposite sides of the strip made in step 4. Or alternatively make it with the opposite placement as shown in step 4.
- . Negative or B Block - Using a 1/4" seam sew a strip made in step 4 to the opposite sides of the strip made in step 2.
How to Iron a Nine Patch Block
Pressing the nine patch block is an important step to help the strips sit together nicely. On Block A press the seams inward toward the middle strip. On Block B press the seams outward toward the top and bottom strips.
The rows will now have the seams facing in the opposite directions. The outer strips seams will be facing inward and the middle strip seams will face outward. When joined, the seams will "lock" in place so they can fit together and the seams will match.
How To Nest Seams for a Nine Patch Block
As you can see in the photo below the seams on the adjacent rows face the opposite directions. The stitch lines are still able to line up so when the rows are placed together you will have a perfectly joined seam.
- To nest the seams, place the strips right sides together. The seams pressed in the opposite directions from one another will join together, as shown below, and will form a "lock" of sorts so that the blocks will not move or shift apart as easily and when sewn, the squares will line up perfectly. It also removes excess bulk.
- If the seams allowance were both press the same direction, the seam would be much bulkier, and would be more likely to slip and shift out of place and the squares would not line up as nicely.
As you can see on the finished 9 patch block below, the stitch line travels straight across all the squares, while the seams on the outer and inner strips are pressed in the opposite directions, as shown in the first photo.
Press the vertical seams to one side to finish.
How to Square Up a Nine Patch Quilt Block
- When sewing a nine patch block, it is important to start with a consistent seam allowance. I highly recommend using a scant 1/4" seam allowance. If your seam is consistent there will be less squaring up that you will need to do.
- Even with a consistent seam allowance I find that I still need to square up the nine patch block so that all side of the block are equal before I sew it to another block.
- Since the middle square will be smaller than the other squares that have not been sewn yet, I find the easiest way to go about square up is to use a square ruler.
- Center the diagonal line on the ruler down the diagonal of the nine patch. The line should travel from the corner of one block, through both corners of the middle block, to the outside corner of the last block.
- Once you have achieved this, then look to the bottom and left edge to find the finished block dimensions. In this case, the block needs to be 4.25". Once you have made sure that the block is at least the finished dimensions, then you able to trim the top and right sides.
- Turn the block 180 degrees and repeat the steps above. You will now have a perfectly square block that is the correct size.
Nine Patch Block Sizes Chart
Nine Patch Block measurements can be calculated with an easy formula. You will need to add the seam allowance to come to the size needed.
To find the block size needed, follow the formula below:
Individual Square Size = (Finished Block Size + 1.5")÷ 3
To figure out what size block you will need to cut, first you need to know what the finished block size you need , then add 1.5" for seam allowance, and then divide this number by the number of blocks you are using which is 3.
You can also use the chart below or print out the pdf by clicking the picture.
If you are going to use the strip piecing method, use the cut square size for the height and cut the strip the width of the fabric.
For a 1.5" finished size block, cut three (3) 1" x WOF strips and then subcut the pieced row into 1" x 2" strips.
Nine Patch Block Layouts
There are countless variations that can be made with the nine patch block. Some will work better using a strip piecing method than others. All of these can be made block by block and using scraps. Here are some great nine patch block variations to inspire you.
Click to Download the Nine Patch Block PDF Cheat Sheet
Print the Nine Patch Cheat Sheet PDF to have as a quick reference.