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To cut quilting half-square triangles (HSTs), cut squares whose sides are the desired finished unit width plus 7/8 inch, then cut each square once diagonally. For quarter-square triangles (QSTs), add 1-1/4 inches and cut the square along both diagonals. These are cutting sizes for units that will be sewn; use the finished size specified by your quilt pattern.
What the size allowances mean
The allowances account for the fabric used in seams. They are applied to the finished width of the triangle-square unit, not to the side length of an individual triangle. For example, a 3-inch finished HST unit starts with a 3-7/8-inch square; a 3-inch finished QST unit starts with a 4-1/4-inch square. The cutting method and both size formulas are described in the American Patchwork & Quilting tutorial.
Patterns can use “HST” or “QST” casually to mean either the cut triangles or the sewn square unit. Check whether the pattern is specifying a finished unit size or a cut size, and follow its seam allowance and instructions if they differ from the general formulas here.
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- Country Of Origin: United States
- Model Number: R98
- Item Package Dimensions: 6.4566929068" L x 6.3779527494" W x 0.7086614166" H
- Item Package Weight: 0.220460011860748 lb
Prepare fabric and tools
- Square up the fabric, then square one end of the strip before measuring and cutting pieces.
- Use a ruler to guide the diagonal cuts. A rotary cutter and cutting mat are useful companions for ruler-guided fabric cutting.
- A large square rotary-cutting ruler is another option for QST cutting, according to the American Quilter’s Society.
- A specialty 45-degree triangle ruler is optional; it is not required for the basic method. Prym lists such rulers among its patchwork rulers.
Cut half-square triangles
- Decide the finished width required by the pattern. Add 7/8 inch to get the square size to cut.
- Cut a fabric strip to that width and square one end.
- Cut the strip into lengths equal to its width to make squares.
- Place the ruler from one corner of a square to the opposite corner and cut once along the diagonal. Each square becomes two equal right triangles.
For a 3-inch finished HST unit, cut a 3-7/8-inch strip and 3-7/8-inch squares, then cut each square once diagonally.
Cut quarter-square triangles
- Decide the finished width required by the pattern. Add 1-1/4 inches to get the square size to cut.
- Cut a fabric strip to that width and square one end.
- Cut the strip into lengths equal to its width to make squares.
- Place the ruler from corner to corner and cut along the first diagonal. Leave the pieces in place.
- Position the ruler across the opposite diagonal and cut again. Each square yields four equal triangles.
For a 3-inch finished QST unit, cut a 4-1/4-inch strip and 4-1/4-inch squares before making the two diagonal cuts.
Rank #2
- Trims Multiple Sizes: Ruler trims 11 sizes of half-square triangles! Streamlines the quilting process. Its multiple sizes eliminates the need for separate rulers for different block sizes, making it a convenient and efficient tool for quilters of all skill levels.
- Accurate Cutting with Minimal Effort: Designed for efficiency and precision, this ruler lets quilters align once and make two cuts to trim all four sides of half-square triangles. There is no need to rotate or realign during cutting. This method speeds up cutting time, ensuring every piece is square, uniform, and ready for assembly in your quilt designs.
- Exclusive Slotted Design: The slotted edge design removes dog ears while trimming, a common challenge in quilting. By eliminating this step, the trimmer improves accuracy in block assembly and saves time, making it easier for quilters to produce flawless, clean-cut quilt blocks.
- Versatile Quilting Tool for Various Techniques: This ruler isn’t limited to half-square triangles; it’s also efficient for squaring hourglass blocks, strip piecing, and strip-tube methods. Its versatility makes it essential for quilters looking to expand their techniques and creativity.
- Durable Acrylic Construction with Easy-to-Follow Instructions: This clear, high quality, acrylic ruler is designed for longevity. It features printed instructions on the ruler, allowing quilters to follow cutting guides easily without needing separate instructions, improving efficiency.
Choose the triangle type your pattern calls for
HST and QST are not interchangeable cuts: use the unit specified by the pattern. QSTs can place the fabric’s straight grain along the triangle’s long edge, which adds stability. The American Quilter’s Society identifies large setting triangles in on-point layouts as one use for QSTs. The different grain orientation and the distinct cutting allowances are the practical reasons to keep the two methods separate.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Left- and right-handed cutting
The ruler placement and diagonal direction can be mirrored to suit the hand holding the ruler or cutter. The AllPeopleQuilt instructions provide left- and right-handed versions of both cuts. Keep the same square size and make the same one-diagonal cut for HSTs or two-diagonal cuts for QSTs; mirror the setup rather than changing the measurements.
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Best Value
- Adequate to Meet Your Needs: you will receive 2 pieces of triangle rulers in the package, very useful for DIY projects in daily life; The sufficient quantity can meet your needs for various situations, and you can also share them with your family or surrounding friends
- Thoughtful Color Design: designed in the transparent color, the folded corners quilting ruler allow you to see the numbers on its surface clearly; With clear prints, it can provide you with lots of convenience when you do some handmade crafts
- Enjoy Crafting Time: the folded corners ruler is suitable for you to DIY with others, you can use your imagination to create many crafts in your own style, which is a nice way to show your preference and taste
- Extensive Usages to Apply: the triangle square ruler can help you create many different patterns, ideal for sewing, cutting, quilting, and more; You can also use it in your home, craft rooms, play rooms, schools, and other places you want, it is nice for beginners and experienced people
- Ideal size for use: the ruler triangle tools measure 5 x 5 inches and 10 x 10 inches respectively, small and portable, light weight, easy to store and carry in school bags, school bags, stationery bags, tool boxes, etc.
Rank #4
- 【Variety of Sizes & Essential Quilting Tool】This 6‑piece tall triangle quilting ruler set includes 6”, 8” and 10” wedge triangles, making it a must‑have for beginners and experienced quilters. Perfect for patchwork, quilting, blankets, doormats, tapestries, and many other sewing projects.
- 【Durable Acrylic Construction】 Each quilting template is 0.118” thick and made of high‑quality acrylic resin, offering excellent durability for repeated use in patchwork, quilting, blanket making, and various sewing applications.
- 【Reduce Fabric Waste】 These triangular rulers help minimize fabric waste. The 6”, 8” and 10” sizes allow efficient fabric cutting and accurate square cutting, making the most of your materials.
- 【Easy to Use】 Simply peel take away the protective film before use. The quilting rulers feature clear 1/2”pattern lines, easy‑to‑read markings, and smooth edges for precise measurement and clean cutting.
- 【Satisfaction Commitment】Quick solution guaranteed. Contact the seller immediately with any questions after purchase. The seller will respond promptly and work to resolve any issue to your satisfaction.
Rank #3
- Versatile Sizes: the package includes 3 differently sized triangle rulers: about 8 inches, about 9 inches, and about 10 inches; Having variety in the sizes available provides the flexibility needed for various patchwork, quilting, and sewing works
- Reliable Material: the acrylic triangle ruler is made of acrylic material, ensuring its durability and longevity; This quality material contributes to the ruler's robustness, enabling you to make precise measurements for your quilting, sewing, or crafting needs without fearing it will break or get warped
- Vibrant Color: our 60 degree triangle ruler is a bright clear color, which not only adds aesthetic appeal to your craft tools but also makes the marking and lines much more visible, catering to better detailing; This distinct color ensures visibility against most fabrics, bringing convenience to your work
- Convenient Design: with its clear markings and edges, the acrylic 60 degree triangle ruler allows for convenient and accurate measurements; Its convenient design ensures that both beginners can use the tool, leading to a smooth and enjoyable crafting experience
- Easy to Use: peel off the film on both ends of the quilt ruler, choose the templates you need, and use them to help you create different quilting creations; This ruler features graduated grid lines from 1 inch to 9 inches suitable for patchwork, quilting, blanket making and sewing projects
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