Accidental Quilt Block Tutorial- Updated

I realized I did not sew and show the block the way I originally intended when I wrote this tutorial!  So I updated it with some new pictures and text.

A couple of years ago I became fascinated with the Disappearing Nine Patch quilt block and decided to experiment with it.  I loved how you could take one block, sub-cut it, and sew it back up to make a different block.  So I took that concept and went a little farther resulting in this block OR this block (depending on how you sew sub-cut triangles together):

Accidental Quilt Block Correct



Here’s how I made it:

I started with a Charm Pack (pre-cut 5 1/2 inch squares) and made a nine patch block.  To end up with the green and red partial “frames” around the block, it’s important that you lay your colors out as pictured here.


I then cut this block in half vertically down the center, then horizontally across the center.



To find your centers line up your ruler with the 2 1/4 inch mark running along the left seam vertically, make your cut, then without moving the block, switch your ruler to horizontal with the 2 1/4 inch mark running along the horizontal seam (as pictured above) and make that cut.  You now have four squares.


Time to sub-cut those squares one more time.  Each square should be cut diagonally as follows to achieve the same result I got:

The bottom left square should be cut from the right lower corner up to the left top corner as pictured below.


The bottom right square should be cut diagonally from the left bottom corner up to the right top corner as pictured below.


The top left square should be cut diagonally from the left bottom corner to the right top corner as pictured below.


The right top square should be cut diagonally from the right bottom corner to the left top corner as pictured below.


You end up with a diamond-shaped cutting pattern as below.


Using the four center triangles, take one top and one bottom triangle put them right sides together and sew a 1/4 inch seam along the diagonal edge to form a square. Take the other two triangles and sew them together as well.  You now have two “accidental” blocks.

Depending on the block you desire, you can sew the triangles together in two different ways.

Block One is my favorite, as I do not know how you can achieve this look in an easier way:

Accidental Quilt Block Correct

Block Two can be constructed using just squares and triangles, but is also another result you can get:


The blocks measure about 6 1/2 inch square.  There will be a couple of dog ears you should trim off before sewing your blocks together.

I have taken images of these blocks and tried out the two following layouts as example quilt patterns that could result from the blocks.  The “cross” one is kind of wonky due to the images not fitting together really well, but I think you get the point.

Here is an example using Block One:

Sample Quilt2

Here is an example using Block Two:

Accidental Quilt Example 2

The four outer triangles can also be sewn together to make squares that look like this:

Accidental Quilt Block Tutorial Secondary blockAccidental Quilt Block Secondary 2

Examples of a couple of quilt layouts using only these blocks are below (again, these are just block images pasted together so not perfect):

Secondary Quilt Example1

Secondary Quilt Example2

I haven’t tried combining all four examples of blocks together, but I think this shows there are several options for making quilts from blocks cut from this technique.  A little more thought into the fabric chosen rather than what I just threw together might result in some really interesting quilts!

If anyone makes quilts from this technique I’d love to see them.

118 thoughts on “Accidental Quilt Block Tutorial- Updated

  1. Francine

    Has anyone figured out how to make this work out? I’ve tried and tried and can’t make this work as pictured. I’m guessing that when you make the 9 block square and cut it as directed, that only have of those triangles made go into the Cross quilt and the other half go into one of the other quilts? And like Emalee stated in an earlier question, my colors match up in the same way that hers does. The cross quilt is beautiful but I don’t want to make two different quilts to use the blocks. Can the designer of this quilt please comment on how she did this?

  2. debbiers

    In reference to the “accidental quilt block” pattern: I finally figured out that this is a (3) different quilt pattern. Each quilt comes from the original 9 block pattern. Each quilt is a small quilt. Hope this helps others who are trying to figure this one out. Have a blessed day!

  3. debbiers

    I have been trying for a few days now to duplicate the ‘Accidental Quilt Block’ with no success. I have done everything as shown in the above pictures, however when it comes to putting everything together the blocks made do not give me the design as pictured above. Please let me know if i can email you a copy of my pictures and see if you can detect what i am doing wrong. Thanks for your help. Look the design, hope i can make one like it.
    Have a blessed day!

  4. Arwen

    This is exactly what I was thinking of for my son’s “off to college” quilt. How big is the BLOCK ONE you showed. Am I understanding correctly in that Block One is only the inner triangles? I don’t have alot of quilting experience, but want to make sure his is about twin size.

  5. moon510

    Question for anybody: how many blocks (of the original block before cutting into D9P –disappearing 9 patch ) do you need to make let’s say a baby quilt? Reason I ask is because if I use a charm pack, most will have different patterns and to make this D9P you will need many of the same patterns of squares to make D9P.

  6. Razz

    I am confused on how the directions say to cut the 9-patch block. You start be using 5.5 inch squares to make the 9-patch block. Therefore, the center square of the 9-patch should be a 5 inch finished square. If you want to cut the block in half vertically and horizontally, it seems to me that you would need to cut 2.5 inches from the seams stated in the directions instead of 2.25 inches.

  7. Emalee

    Question on disappearing 9 quilt using using block 1. I’m having problems getting the colors to match up with block 1. Can you explain how to get the part that looks like a cross to look like that. When I put mine together instead of having red and green alternating, mine has two sides alternate green and red the other two are either solid green or solid red. I have no idea what I’m doing wrong. Any assistance would be greatly appreciated.

  8. Jill

    I love the way you are experimenting with the D9P. (Disappearing 9 Patch). I saw that abbreviation somewhere and loved it. I too am making a D9P quilt (2 twins actually) and it is going very fast. I think I’ll use your extra sub-cut for a couple of pillow shams! You’ve done a great job showing us how the triangles can be manipulated, Thanks for the inspiration!

  9. Anonymous

    I love this, this will be my second quilt, my first one was just blocks sewn together, I’, excited about how you can get different looks.

  10. Helen

    I’m excited to give this a try. I’m going on vacation and will be looking for fabric specifically for this quilt. Thank you.

  11. Pingback: Secondary Patterns | heARTS Creations


    Hi,I check your blogs named “Accidental Quilt Block Tutorial- Updated | Beyond Sock Monkeys ~ My Quilting Adventures” daily.Your humoristic style is witty, keep doing what you’re doing! And you can look our website about proxy server list.


Comments Welcome

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s