Positive and negative colorations add pizzazz on garment seams.
Enhance color-blocked seams on garments or other projects with positive/negative embroidery. As with every embroidery technique, there's more than one way to achieve the same end result. In this case, you can use the same embroidery motif on each design half by using two colors of thread and fabric; use embroidery software to add "stops" and/or color changes within a single design; or split designs using appropriate embroidery software.
Look for designs with a flat edge, such as border motifs, monogram letters or geometric shapes. Consider working with one design on either side of the seamed area or a two-color design that has the desired effect already digitized into the stitches.
The color-blocked seamed area must be flat for embroidery. Depending on the fabric weight, prepare the fabric sections for embroidery:
For lightweight fabrics, such as cottons or knits, add extra seam allowance width to the seam where the design will be sewn. Add enough on both sides to back the entire embroidery design when it's pressed open. For example, if the design is 1" wide, add a 1 1/4" seam allowance onto both pattern piece sections. Sew the sections together and press the seams open. The extra-wide allowances provide a flat base for the embroidery without it "falling off' the edges of a standard seam allowance. Stitching over uneven layers can distort the design.
For knit fabric, use a cut-away stabilizer behind the embroidery design. For woven fabric, use a tear-away stabilizer.
For heavier fabrics, such as melton or fleece, join fabric sections together at the stitching line with a 6mm-wide, open decorative stitch. Cut away the seam allowance on both fabric sections. Cut a piece of lightweight cut-away, mesh stabilizer larger than the finished embroidery design width by the seam length. Place the fabrics right side down on a flat surface and abut the edges. Use temporary sprayadhesive to secure the stabilizer to the fabrics, centering thestabilizer over the stitching line. On the right side, using monofilament thread, sew the decorative stitch over the abutted seam edges. Don't remove the stabilizer.
Hoop a layer of lightweight cut-away, mesh stabilizer, spray it with temporary adhesive and secure to the wrong side of the fabric to be embroidered. Use perimeter basting or the "fix" function on your machine to hold the fabric and stabilizer layers together. Or, baste the layers together on the sewing machinebefore embroidering. Embroider the design over the flat seam, being careful to center the seam exactly at the color break. Cut away the stabilizer close to the decorative stitching and the embroidery, and complete the project according to the pattern guidesheet (1).
Design Alignment
For the best results aligning the designs over seams, embroider a sample of the chosen design with black thread on white fabric that is the same or a similar weight and texture as the project fabric. Remove the hoop from the machine, but don't remove the fabric from the hoop. With a thin-line permanent marker, draw just inside the inner hoop directly on your sample fabric; label the design upper edge with a small arrow and mark the center point and hoop notches.
Unhoop the sample and press it flat. Scan or copy the fabric image onto transparency film and use it as a template to mark the design placement on the project fabric. Keep in mind the fabric weight makes a difference in the end result. If using a lightweight woven fabric, the template will be accurate. If you decide to stitch the design on a heavier fabric than the test sample (such as melton or fleece) the stitches will imbed in the fabric and pull the design out of alignment. Test-stitching designs on light-colored fabric with a dark thread color is the best way to determine the accuracy of placement templates.
Before positioning the project fabric, draw lines on the stabilizer between the hoop notch marks as a guide for seam placement.
Two-tone Mania This fun embroidery technique can be used to add a bit of creativity to your next project.For patterns with straight front or back seaming, add extra-wide seam allowances to the pattern pieces to support embroidery. Avoid embroidering over intersecting seams; the additional bulk may cause distortion.
Experiment with this technique on shirt yokes and sleeve seams.
Appliqués are perfect for positive/negative imaging.
Don't forget non-wearable items for this technique, too! Create wonderful handbags, backpacks, tote bags and home accessories using positive/negative imaging.
Combining Designs
It's possible to combine a multitude of designs using embroidery software if you have a large embroidery hoop. Open designs in customizing embroidery software. Turn on the grid feature, and position the design centers along the horizontal or vertical hoop alignment position marks (2). Save the combined design in a new file.
Stitch Altering
In stitch editing or digitizing embroidery software, it's possible to alter designs by adding "stops" and color changes.
Import the designs into embroidery software that allows you to change stitches. Change all the thread colors to one color for easy editing. Using the grid feature, position the embroidery design centers along the horizontal or vertical hoop alignment lines in the software window. Zoom in on the area where stops or color changes will be added and follow the embroidery software manual to add the stops to the design(s). Color sort the design after the changes so like colors will stitch together (3).
Design Splitting
Another option for two-tone designs is to split the design. In embroidery software, change all the thread colors to one color for ease in splitting. Some design splitting software creates two or more files from a single design for separate hoopings, depending on the available hoop and the design size. Use the software to split a single design into two separate files, then change the thread colors in each file. Use customizing software to recombine the two separate files into a single file. If you have a larger hoop, open several design repeats to fill the embroidery hoop.
Jeanine Twigg is the author of the Embroidery Machine Essentials series published by Krause Publications. This series includes Embroidery Machine Essentials, More Embroidery Machine Essentials, and two Companion Project Series books- Basic Techniques and Fleece Techniques. She is also the contributing editor of Creative Machine Embroidery.
This fun embroidery technique can be used to add a bit of creativity to your next project.For patterns with straight front or back seaming, add extra-wide seam allowances to the pattern pieces to support embroidery. Avoid embroidering over intersecting seams; the additional bulk may cause distortion. 
