How to Baste 2-1/2 Inch Scallops for Smooth Curves

By Paper Pieces for English Paper Piecing | Published: 2026-10-20

Category: How-to Guides

Learn the best method to baste 2-1/2 inch scallops for English paper piecing. Get smooth curves every time with these simple steps.

Quick Answer

To baste 2-1/2 inch scallops for smooth curves, use a 1/4 inch seam allowance and clip the inner curve before basting to prevent puckering.

Why Scallops Need Special Basting

Scallops have alternating convex and concave curves that can pucker or gap if basted incorrectly. The 2-1/2 inch size is large enough to handle easily but small enough that precision matters. Clipping the inner (concave) curve before basting releases fabric tension and allows the paper piece to sit flat.

Using a windowed paper piece helps you see the seam line, but standard paper pieces work fine if you mark the seam allowance with a fabric pen.

Step-by-Step Basting Guide

Step 1: Prepare the Paper Piece and Fabric: Place the 2-1/2 inch scallop paper piece on the wrong side of your fabric. Cut the fabric leaving a 1/4 inch seam allowance around the paper. If your paper piece has a pre-printed seam line, align the edge of the fabric with it. Check that the fabric grain runs straight along the scallop's flat edge to avoid distortion.
Step 2: Clip the Inner Curve: Snip small (1/8 inch deep) notches into the seam allowance along the concave (inner) curve. Space clips about 1/4 inch apart. This releases tension and lets the fabric fold smoothly over the paper. Do not clip past the seam line or the paper piece will peek through.
Step 3: Baste the Outer Curve First: Fold the seam allowance over the paper on the convex (outer) curve and secure with a thread basting stitch or glue. Work from the center of the curve outward to distribute fabric evenly. Basting the outer curve first stabilizes the shape and makes the inner curve easier to manage.
Step 4: Baste the Inner Curve: Fold the clipped seam allowance over the paper on the concave curve. Use small, even stitches or glue dots. The clips should close slightly as you pull the fabric taut but not so tight that the paper warps. If the fabric puckers, you clipped too little; if the paper shows, you clipped too deep.
Step 5: Check and Press: Once all edges are basted, finger-press the fabric to set the creases. Place the basted scallop on a flat surface and check that the paper lies flat without bulges. Adjust any loose spots before sewing. A smooth basting now prevents wavy seams when you join scallops later.

Product Facts

2-1/2" Scallops: 2-1/2" Scallops from Paper Pieces are available with a 1/4" seam allowance option. Choosing the 1/4" seam version saves you the step of marking your own seam line and gives consistent results every time.
2-1/2" Scallops