Monday, December 31, 2007

TriMiters - A Felted Bag

I finished the mitered triangle bag! I'm really pleased with the results. I designed this bag to wear with jeans. My favorite "what do you wear when it's not really dress up, but not exactly casual" outfit is a pair of totally expensive jeans with a long black cabled sweater and black turtleneck. This bag goes perfectly with my trendy duds and gets lots of oohs and aahs.

I call it TriMeters - it's based on mitered triangles tumbling in a pinwheel pattern across the body of the bag. The written instructions are much more complicated than the process - once you've knitted one triangle, it all flows quite logically.


A mathematical felted handbag by Knitternall


  • 2 skeins black worsted wool
  • 1 skein denim blue worsted wool (I used Cascade 220 for both)
  • Size 10 1/2 straight needles
  • Size 10 1/2 circular needles
  • Size 10 1/2 double-pointed needles
  • Four silver D-rings
  • Set of black shoulder-length purse straps (I found mine at

The main design for this handbag is based on a mitered triangle. Six contiguous triangles create a pinwheel pattern across the main body. You will begin with the pinwheel section, four sets of six mitered triangles.

SK2po: slip 1 purlwise with yarn in back, knit 2 stitches together, pass slipped stitch over (also known as a double decrease).

SSK: Slip 2 stitches purlwise, knit both together through back of stitches.

K2tog: Knit two stitches together knitwise.


SECTION 1: Pinwheel Mitered Equilateral Triangle Pattern
(You will change colors on the right side - RS.)

With 10 1/2 straight needles:
Row 1: (RS) With blue wool, cast on 37 stitches using long tail method.
Row 2: (WS) K17, SK2po, K17
Row 3: With black wool, K2tog, K14, SK2po, K16
Row 4: K2tog, K13, SK2po, K14
Row 5: With blue wool, K2tog, K27.

Row 6: K2tog, K11, K2po, K12
Row 7: With black wool, K2tog, K9, SK2po, K11
Row 8: K2tog, K8, SK2po, K9
Row 9: With blue wool, K2tog, K17
Row 10: K2tog, K6, SK2po, K7. Break blue wool (you'll weave in end later).
Row 11: With black wool, K2tog, K4, SK2po, K6
Row 12: K2tog, K3, SK2po, K4
Row 13: K2tog, K1, SK2po, K3
Row 14: K2tog, SK2po, K1
Row 15: K1, K2tog, pass second stitch over first stitch, and fasten off.

Pinwheel Diagram

Pinwheel #1

Follow instructions for Basic Mitered Equilateral Triangle to knit Triangle #1.

With right side facing, pick up 19 stitches along base of Triangle #1 (you just cast off in the middle of the base).

Cast on 18 stitches. You now have 37 stitches on your needles.

Triangle #2: Follow instructions for Basic Mitered Equilateral Triangle. You now have two triangles.

Triangles #3 - #6: Continue this pattern, always picking up stitches form the base of the previous triangle, until you have five triangles completed.

To close the pinwheel, seam together Triangle #6 to Triangle #1 with blue wool yarn.

Pinwheel #2

Cast on 19 stitches. Pick up 18 stitches from any side of any triangle in Pinwheel #1.Follow instructions for Basic Mitered Equilateral Triangle, and create 6 new triangles for Pinwheel #2.

Pinwheel #3

Pick up 19 stitches from Triangle #4 of Pinwheel #2. Follow instructions for Pinwheel #1.

Pinwheel #4
Pick up 19 stitches from Triangle #4 of Pinwheel #3. Follow instructions for Pinwheel #1.Join Pinwheel #4 to Pinwheel #1 by seaming sides of the continuous triangles (Triangle #4 in Pinwheel #4 and Triangle #1 in Pinwheel #1) with blue wool yarn.

The center row of pinwheels is now complete.

Now, create a straight field for the pinwheel by knitting mitered triangles in black wool along the top, between the 5th triangle of one pinwheel and the 6th triangle of the adjacent pinwheel. These are NOT equilateral triangles as in the Pinwheel. The angle is much wider, so these mitered triangles will bind off to fit the new angle.

Mitered 120 degree Triangle Pattern
With black wool

Row 1: With RS facing, pick up 37 stitches, 19 from Triangle #5 and 18 from Triangle #6 in adjacent pinwheels.
Rows 3, 5, and all other odd rows: K2tog, knit to center 3 stitches, SK2po, knit to last 2 stitches, K2tog.
Rows 2, 4, and all other even rows: Knit across.
Repeat last two rows until you end with K2tog, SK2po, K2tog.
Knit a row.
Sk2po and fasten off.

Knit the same triangles across the bottom of the pinwheel row, between the 2nd triangle of one pinwheel and the 3rd triangle of the adjacent pinwheel.

SECTION 2: Top Of Bag

With black wool and 10 1/2 circular needles, with RS facing, pick up stitches along tops of Mitered 120 degree Triangles. Knit in round until this section is 2-3" from pick-up row. Bind off.

With blue wool, add knitted I-Cord trim between Mitered 120 degree Triangles and 2-3" black border by picking up stitches from triangles.

I-Cord Trim

Cast on 5 stitches on a 10 1/2 double-pointed needle.
*Slide the stitches back to the beginning of the needle.
Knit 4.
Knit the 5th stitch together with the next stitch in the mitered triangle. Do not turn.
Move the needle with the stitches to left hand.
Pull the yarn across the back of the cord and slide the stitches to the other side of the double-point needle.*
Repeat from *.

When beginning and end of I-cord meet, bind off and weave ends together to create a smooth line.


With black wool and tapestry needle, stitch base together.

Felt bag: Place bag in zippered laundry bag. With a small amount of detergent, wash in hottest possible water cycle of top-loading washing machine, checking in ten-minute increments for felting progress. Once you're satisfied, let bag go through rest of rinse/spin cycles.

Block bag by stretching and pulling until it's fairly straight, then placing it on a large box wrapped in plastic. Add more plastic bags until bag has a firm form. Let air dry (may take 2-3 days).

Attach your choice of handles. I used leather straps and d-rings. I made small holes in the felted wool with a seam ripper, just big enough for d-rings to pass through. I then added leather straps, as seen in photo.)

Thanks to Michelle (Michelle's Romantic Tangle), here's a suggestion for the myriad ends these triangles produce. Make sure they're on the "inside" of the bag. Then, after you felt it, CUT THEM OFF! You don't have to weave them in! Thanks, Michelle, for helping me update these directions.

I welcome suggestions and questions and will gladly clarify the instructions as needed!


  1. Thanks for the bag pattern. I was looking for something similar to this, and just love it. Can't wait to knit it.

  2. Your pattern is delightful! I love the look of the finished bag, but I also love the interesting process to get there! Thank you so much!!

  3. A beautiful bag to include in my wardrobe.
    Thank you so much for sharing your talent!

  4. I love felted bags and I love using mitered shapes; therefore, I think your bag is awesome. I copied the pattern, and once I finish it (no time frame, however), I'll let you know how it came out.
    Thank you so much for posting the pattern!

  5. I love miters. This is beautiful.

  6. Your compliments are wonderful! I'm delighted you like the design.

  7. Hello:
    I am starting to knit the TriMiters purse as a gift for my daughter's h.s. graduation. I have a question regarding the bottom of the purse:
    is it knit from a series of black pinwheels, forming a circular bottom, or is the purse a flat rectangular shape? Thank you in advance,
    Martha, Wisconsin

  8. I'm delighted you want to make this pattern as a gift! The bottom is a flat rectangle. When you seam it together, before felting, the bag looks like a flat "envelope." But once felted, you'll shape it and flatten the bottom for drying. The bottom ends up slightly rounded in the finished piece.

  9. I just finished the bag for my daughter. I made some mistakes but it still came out really beautiful. It wasn't as hard as I thought.

    I'm going to start the tote soon.

  10. LoreD, that's wonderful! I hope you'll post the picture some time. I love seeing all the variations of Trimiters. Each bag is delightfully unique.

  11. WOW, that is so pretty!

  12. what are the dimensions after felting? would love to try this classy-looking bag.


  13. The dimensions vary depending on the degree of felting. My original bag is approximately 12" high and 15" wide (without the straps), but I've seen completed bags both smaller and larger. Like most felted projects, there's a bit of mystery until you pull yours out of the washing machine and block it. Remember - the longer you wash/agitate it in super hot water, the smaller it'll get!

  14. as i prepare for this project, a few more questions come to mind:

    1. the bottom i-cord does not seem to be mentioned in the instructions--shall i assume it is done same as the top one?

    2. am new-ish to knitting and do understand CO; but what does "fasten off" mean?

    3. what size box would you recommend i have on hand for the stretching process after felting?

    linda g

  15. The icord "frames" the midpanel, which is made up of the triangles. Fasten off and Cast off mean the same thing. The box depends on how much your bag felts. Just use whatever you have on hand. I used a cereal box (still filled with cereal) wrapped in a plastic trash bag!

  16. you've been so kind to be responsive. thank you for your help! it will add depth to the appreciation of your beautiful creation.

    linda g

  17. I have 2 "math" questions:
    For the 120 degree miters we pick up 37 stitches and decrease 4 sts every RS row. Where I find a snag is ending up with 7 sts to do the second to last row (K2tog, SK2po, K2tog). My math makes the row counts as follows: 37/33/29/25/21/17/13/9/5.
    Am I missing something?

    Somewhat related is the instruction for starting the top of the bag which reads, "pick up stitches along tops of mitered 120 degree Triangles." Do I pick up 1 st per row (which works out to 18 using the decrease schedule mentioned in my last paragraph) or another number?

    I love the way this is turning out so far, and I know that felting is very forgiving, but I want to give it the best shot. I know that knitting shrinks differently in length and in width and here we have the pinwheels knit in 3 directions, but the top and bottom sections are knit in the conventional 2 directions, so I am not sure how to apply that to how many sts I should pick up around.

  18. What is the final measurements of the bag after felting?


Thanks for sharing your thoughts - it's great to hear from you!