Lava Meets Sea Half Square Triangle Quilt (With Tips to Make Your Own)


Lava Meets Sea Finished

This is possibly my favorite quilt, and it’s certainly the one that has had the most “how can I make one” questions as I was making it, so I thought I’d share some tips on how to make your own.

First, the story behind it:  This quilt is a gift for my best friend Kim, who is engaged to Matt.  I wanted to make a quilt for them that would illustrate the blending of two hearts, two lives and two families.  I named it Lava Meets Sea, because when lava hits the sea it makes rock, a strong foundation.

Lava Meets Sea Quilt Tilted

To start yours, decide on the colors you’d like to use.  To make it easy on myself, I bought bundles of fat quarters of coordinating reds and blues.  Both are Colorstory Fat Quarter Bundles by Robert Kaufman.  The red is called Hot Spice, the blue is Grecian Waters.  This gives you a wide range of lights and darks in each color to work with, but keep in mind that this quilt is based on value (the depth of color) as much as it is on color itself.  Be sure when choosing your colors and making your blocks that you continue the pattern of dark and light even as you change colors.  With the bundles of colors I chose, the red bundle is darker than the blue, so notice how the colors meet in the middle of the quilt.  The darker shades of the red are used with the paler shades of blue to keep the dark and light values moving through the center of the quilt where the colors meet.  It is very important that you not rely on the different colors to create the effect, make sure you’re keeping the dark and light values even through the color changes.  That might be easier to see from this photo where I was first laying out blocks.

Kim's Quilt Progress Blue

Here’s my super fancy chart.  Notice that this was not meant to be shared with the public, as I even wrote my optometrist appointment reminder at the top of the page.  *Sigh*  This makes a generous lap sized quilt, big enough to share for a nap on the couch.

Fancy Lava Meets Sea Quilt Chart

If you follow my chart, you’ll want to cut 201 red squares and 195 blue squares for a total of 396 squares.  Then you’ll want to make 127 red blocks, 121 blue blocks and 148 mixed blocks for the middle.  (I’m not sure that I kept completely to the chart, but it is helpful when you first start laying out the blocks.)  You can see how I separated my colors into two stacks each of dark, medium and light, one for the “solid” red (or blue) and another for the mixed (middle) area.

Kim's Quilt Process 3

The blocks for this quilt are the most simple blocks you can make, half square triangles.  Even if you’re new to sewing, with just a little practice you can make perfect blocks.  There’s a full tutorial here if you need to learn the method.  (I started with five inch squares just as in the tutorial.)  The tutorial will explain to separate colors into dark, medium and light and then mix them together to get the contrast you need for each side of the block.  By looking at the photos here, you should be able to lay out the blocks to form the diamond pattern that flows across the quilt.  Remember, if you’ve made half square triangles with contrasting values, you can create many different designs just by changing the direction of the blocks.  Play around with them and you may find a design you like more than this one!

Lava Meets Sea Quilt Completed

I chose a plain black binding, something that wouldn’t distract from the strong pattern of the quilt.

Lava Meets Sea Quilt Black Binding

Please let me know if you have any questions about construction, and I’d love to see your photos if you make one!  Please link me up so I can see what you made.  :)

Lava Meets Sea Quilt

Lava Meets Sea Quilt Porch Swing Cushion

Lava Meets Sea Quilt Porch Swing


Chervon Values Quilt

Chevron Half Square Triangle Values Quilt and Pillow

I posted a tutorial recently for making half square triangles, the basis of this quilt and pillow, if you’d like to try it for yourself.  I plan to use half square triangles for a very different style of quilt for another upcoming little one soon, but for now I’ll just enjoy the feeling of accomplishment from this one.

Chevron Quilt

Have a great day!

Values: Half Square Triangle Tutorial


Half square triangles are amazing — one of the most beautiful and versatile quilting blocks, they’re also among the easiest to make.  I especially love the look of a values quilt done in half square triangles.  The contrast between the colors of your triangles allows you to create visual interest and depth.  Here are some photos to show you what I mean.  The squares are in the same position in each of these photos, just rotated so that the light and dark sides make different patterns.

Dark and Light


Dark Center

Light Center


You can see more variations of half square triangles in finished quilts in this Flickr gallery.  Ready to try it yourself?

You’ll want to start with simple squares.  I like to use charm packs, packs of precut five inch squares that usually include prints from an entire line of fabric.  (The fabrics used here are Fossil Fern by Benartex, a fabric line that’s been in print for an amazing 15 years!)

Sort your squares into three piles by color value: light, medium and dark.  Then pair up colors by taking one each from two different piles, placing the lighter on top with right sides facing.  Draw a diagonal line from one corner to another.  (This line won’t be seen, so feel free to use a regular pencil if you like.)


Use the line as a guide to sew a quarter inch seam along one side,

Half Square Triangle Tutorial: Sew a Quarter Inch Seam

then the other.

Half Square Triangle Tutorial: Turn and Sew

Cut along the pencil line and you’ve got two new squares.

Half Square Triangle Tutorial: Cut Along the Line

Press the seam open.  Don’t worry about those wonky little bits that stick out, they’re about to be trimmed off.

Half Square Triangle Tutorial: Iron the Seam Flat

I’ve started with a five inch square, but I’m going to trim it down to 4.5″.  This will allow me to even up the square nicely.  I like to use a square template for this because it’s got handy lines for me to follow, but you can also use the lines along your cutting mat.  For the first cuts, I line up the center seam with a diagonal line on the template and make sure the fabric under the template is still larger than 4.5″, then cut along the right and top edges.  Having that perfect center line will make piecing much easier later.

Trimming Half Square Triangle, First "Squaring Cut"

Flip the fabric around so the two uncut edges are at the right and top again.  Line up the center seam with that diagonal line and make sure the bottom and left edges are at the 4.5″ marks.  Careful cut the top and right sides.

Trimming Half Square Triangle, Second "Squaring Cut"

This will give you a half square triangle made of two perfect triangles.

Finished Half Square Triangle

You’re ready to set them out in different patterns and see how you like them best!  Here are a few of my own half square triangle quilts so that you can see how versatile they can be.  (You can find more details through my Quilts page.)

Half Square Triangle Quilts Collage