Quick answer
Use half-square triangle trimmers to trim HST blocks to exact size after sewing, ensuring perfect points and consistent block dimensions.
Why use dedicated HST trimmers instead of a standard ruler
Half-square triangle trimmers have a diagonal line that aligns with the seam, letting you trim both sides of the block without flipping or repositioning. A standard square ruler requires extra steps and can shift, leading to uneven blocks.
The Half-Square Triangle Trimmers from Mrs Quilty cover 11 sizes with two tools, so you can trim a range of common HST dimensions without buying multiple rulers.
How to trim half-square triangles with HST trimmers
- Press the seam: Press the sewn HST block open, setting the seam flat. Use a hot iron without steam to avoid distorting the fabric. A well-pressed block lies flat and trims more accurately.
- Align the diagonal line: Place the HST trimmer on the block so the diagonal line on the ruler matches the seam line exactly. The seam should be centered under the line. If the diagonal is off, your trimmed block will have uneven points.
- Trim the first two sides: Hold the trimmer firmly and trim along the two exposed edges of the ruler. Use a rotary cutter with a sharp blade and a steady hand. Always cut away from your body and keep fingers clear of the blade.
- Rotate and trim the remaining sides: Rotate the block 180 degrees, align the trimmed edges with the trimmer's marked lines, and trim the remaining two sides. The block is now exactly sized. Check that the seam still aligns with the diagonal after rotating; it's easy to shift.
Product facts
-
Half-Square Triangle Trimmers: Trim 11 sizes of half-square triangles quickly with two precision trimmers. You don't need a separate ruler for each finished size; two trimmers handle most quilting projects.
Half-Square Triangle Trimmers
