This is the most common technique used to sew vertical seams. When done correctly it is virtually invisible from the right side; it is therefore sometimes called a blind stitch seam. There are three main ways to work this seam.
Mattress Stitch version 1
Thread a tapestry needle with matching yarn. If you left a long tail at the beginning of your knitting, use it to begin the seam. When you stretch the knitting slightly sideways, you will see a bar between the first and second stitches from the edge. Insert the tapestry needle under the first bar on the left, and pass the needle under it and back out. Insert the tapestry needle under the first bar on the right, pass the needle under it and back out. Repeat this process to the end of the seam.
Mattress Stitch version 2
This is worked very similarly to version 1. Pass the tapestry under 2 bars between the first and second stitches from the edge. This version works better for thinner yarns. It shows more when the seam is under stress (the fabric stretched widthwise, for example.) Most people prefer version 1 when seaming anything thicker than DK or sport yarns.
Mattress Stitch version 3
This is also similar to version 1. It is done half a stitch from the edge. There is a bar of yarn in the center of the edge stitch. Pass the tapestry needle under 1 bar in the center of the left edge stitch; take the needle all the way under and back out. Pass the tapestry needle under the bar in the center of the right edge stitch. Repeeat this process to the end of the seam.
This version is great for K1, P1 ribbing. When worked correctly, you won't see a seam in the ribbing; it appears to continue uninterrupted around the edge of the garment. Many people prefer this version for seaming the whole garment when working with knitting worsted and thicker yarn, since it creates a much smaller seam
Regardless of which seaming method is used, there will be yarn ends to deal with. The preferred technique is to work them into the seam allowance, whenever possible. Thread the yarn tail into a tapestry needle; sew through the seam allowance on the inside of the garment for approximately 2". Stretch the fabric slightly so that the seaming yarn relaxes; clip the yarn, leaving a scant 1/4". If there is no seam allowance, thread yarn tail into a tapestry needle and sew through the purl bumps on the wrong side of the fabric. Stretch the fabric and clip the seaming yarn.
BEGINNER KNITTING TECHNIQUES
Casting On and Knitting Stockinet
Waste Yarn and Ravel Cord
eWrap Cast On
Backstitch Bind Off
Stitch Through Stitch Bind Off
Transfer Tool Practice
Mattress Stitch Seam
Joining On The Machine
Pick Up A Side Edge
Rehang and Join A Sleeve
Rehang and Join Button Bands
Basic Short Row Techniques
This tutorial was copyrighted and uploaded to the original Clearwater Knits website in 1997.
It was updated July 15, 2016