In sewing, you will primarily encounter three distinct types of corners: inside, outside, and mitered. These corners are fundamental to garment construction and various sewing projects, appearing at virtually any angle, from acute (less than 90 degrees) to obtuse (more than 90 degrees). Mastering these corners ensures a clean, professional finish and proper drape for your fabric.
Understanding the Core Corner Types
Each corner type serves a specific purpose and requires a particular technique to achieve a smooth, flat, and durable finish.
1. Inside Corners
An inside corner is characterized by an indentation or "valley" where two seams meet, creating a concave shape. These are commonly found in areas like necklines, pocket openings, squared armholes, or certain appliqué designs.
- Characteristics:
- Forms a sharp indentation inward.
- Requires careful handling to prevent puckering and ensure the corner lies flat.
- When to Use:
- Creating sharp angles on collars or facings that turn inward.
- Shaped seams for clothing details.
- Internal cut-outs or openings.
- Sewing Tips for Inside Corners:
- Stitch Accurately: Sew precisely up to the corner point, then pivot and continue stitching. For a professional finish, you may reinforce the stitch just before and after the pivot point with a few smaller stitches or backstitches.
- Clip the Seam Allowance: To allow the fabric to spread and lie flat when turned right side out, you must clip into the seam allowance at the corner point. Clip almost to the stitch line, being careful not to cut through the stitches.
- Pressing: Pressing the seam open before turning can help define the corner. After turning, press again to set the shape.
For a visual guide, consider exploring techniques for sewing and clipping inside corners.
2. Outside Corners
An outside corner is the opposite of an inside corner, forming a protruding "peak" or convex shape. These are frequently seen on collars, cuffs, flaps, sashes, and other design elements that extend outward.
- Characteristics:
- Forms a sharp point or extension outward.
- Requires trimming and sometimes clipping to reduce bulk and achieve a crisp point.
- When to Use:
- Collars, cuffs, and lapels.
- Pointed pockets or flaps.
- Anywhere a sharp, defined edge is needed.
- Sewing Tips for Outside Corners:
- Stitch with Precision: Stitch accurately to the corner point, pivot, and continue. Reducing your stitch length around the corner can provide extra strength.
- Trim the Seam Allowance: To reduce bulk and allow the fabric to turn smoothly, trim the seam allowance at the corner point diagonally across the tip, close to the stitching line. You might also need to trim down the seam allowance edges.
- Grade the Seam (Optional but Recommended): If working with multiple layers, trim each layer of the seam allowance to a different width. This helps to further reduce bulk and create a smoother transition.
- Turn and Shape: Gently turn the corner right side out. Use a point turner or a dull pencil to carefully push out the corner to a sharp point, being cautious not to push through the fabric.
- Pressing: Press thoroughly to set the shape of the corner.
Learn more about achieving perfect outside corners for your projects.
3. Mitered Corners
A mitered corner is a clean, diagonal seam where two fabric edges meet at an angle, typically 45 degrees, creating a neat finish without bulk. Unlike inside or outside corners that define a structural edge, mitered corners are primarily used for decorative or finishing purposes, such as on hems, bindings, or borders.
- Characteristics:
- Forms a diagonal seam at the corner, creating a perfect right angle when finished.
- Reduces bulk in hems, borders, and facings.
- Provides a professional and tailored appearance.
- When to Use:
- Hems on garments, curtains, or tablecloths.
- Borders around quilts or decorative items.
- Binding edges for a crisp finish.
- Sewing Tips for Mitered Corners:
- Fold and Press: Fold and press your hem or border allowance to the desired width along both edges that meet at the corner.
- Create the Miter Line: Unfold the corner. Fold the corner diagonally so the fold line aligns with the intersection of the two original fold lines. Press this diagonal fold.
- Trim (Optional): Trim away the excess fabric along the diagonal fold, leaving a seam allowance (e.g., 1/4 inch or 6mm).
- Stitch: Refold the diagonal seam allowance and stitch along the diagonal fold. Trim, press open, and then re-fold your hems/borders.
- Final Press: Press the finished mitered corner for a flat and crisp appearance.
Discover techniques for sewing elegant mitered corners.
Summary of Corner Types
| Corner Type | Description | Common Applications | Key Technique |
|---|---|---|---|
| Inside | Indented, concave shape | Necklines, pocket openings, armholes | Clipping the seam allowance |
| Outside | Protruding, convex shape | Collars, cuffs, flaps, points | Trimming and grading the seam allowance |
| Mitered | Diagonal seam at a corner, reduces bulk | Hems, borders, bindings, facings | Folding, pressing, and stitching a diagonal seam |
Regardless of the corner type, precision in stitching, appropriate trimming, and thorough pressing are crucial for achieving professional-looking results in all your sewing endeavors.
