How to embroider double knit and interlock fabrics

Double knit and interlock are comfortable, versatile fabrics often used for T-shirts, baby clothes, leggings, tracksuits and lightweight jumpers. Their smooth surfaces are excellent for embroidery, but their stretch and soft structure can cause puckering, distorted lettering or a design that feels stiff if the fabric is prepared like woven cotton.

With the right stabiliser, hooping method, needle and stitch density, you can create clean machine embroidery on these knitted fabrics. The same approach works for cotton jersey, polyester knit, ribbed garments and many ready-made clothing items sold through Australian retailers and markets.

Understand the fabric before stitching

Double knit is made from two layers of knitted loops, giving it a stable, slightly thicker structure than single jersey. Interlock is also formed with interlocking loops and usually has a smooth finish on both sides. Both fabrics recover well after stretching, but they can still shift under the presser foot or expand around a dense embroidery design.

Test the fabric by gently pulling it across the grain and along the length. If it stretches easily, plan to use a cut-away stabiliser or a combination of stabilisers. A firmer double knit may manage with a lightweight cut-away layer, while a very soft interlock used for babywear may need extra support to prevent permanent distortion.

The fabric’s weight also affects the design you choose. Small applique motifs, simple florals, line-art animals and open lettering are generally safer than very dense filled designs. EMBMall includes many downloadable embroidery files in floral, animal, seasonal, sports and character themes, so check the stitch count and finished dimensions before purchasing.

Select a design suited to stretch fabric

A design for knitwear should have balanced coverage and moderate stitch density. Excessive satin stitching can pull the fabric into ridges, particularly in large lettering or solid motifs. Designs with underlay, carefully arranged fills and a sensible stitch direction spread tension more evenly across the garment.

For a first project, choose a compact design with rounded shapes and limited thread changes. A small native animal, simple flower, initial, star or sporting emblem can work well on a child’s top, polo shirt or tote made from interlock. Keep the design comfortably away from seams, hems, pockets and ribbed edges, where thickness can interfere with the hoop.

Scale matters as much as style. A motif that looks attractive on a 20-centimetre hoop may be too large and heavy for a lightweight T-shirt. For Australian clothing sizes and everyday garments, a chest emblem around 7 to 10 centimetres wide is often practical, while a larger back design may require a more stable garment and careful testing.

Stabilise the knit without stretching it

A cut-away stabiliser is usually the most reliable choice for double knit and interlock because it remains attached after stitching. Place it on the wrong side of the fabric, with the stabiliser’s adhesive or stabilising surface against the garment if the product requires it. Use a temporary spray adhesive or a few pins outside the embroidery area to hold the layers together.

For lightweight or delicate garments, add a water-soluble topping on the right side. This prevents stitches from sinking into the knit and helps preserve sharp details. A topping is especially useful for small text, satin borders and fabrics with a brushed or textured surface. After embroidery, remove the excess according to the manufacturer’s instructions.

Avoid pulling the knit tight while hooping. The fabric should lie flat and relaxed, with no wrinkles, but it should not be stretched to fit the hoop. Stretching during hooping can make the garment appear smooth while stitching and then create gathers when it is removed.

A magnetic hoop can reduce hoop marks on delicate clothing, although it is not essential. If using a standard hoop, loosen the hoop screw, position the stabilised garment carefully and tighten it only enough to hold the layers securely. For expensive merino-blend knitwear or a favourite Melbourne-made garment, test the full method on a similar offcut first.

Prepare the machine and needle

Use a sharp embroidery needle suitable for the fabric. A 75/11 embroidery needle is a useful starting point for lightweight to medium knits, while a 90/14 may suit a heavier double knit. Replace the needle if it becomes blunt, bent or develops burrs, since a damaged point can create holes or snags in interlock.

Polyester embroidery thread is a practical option for garments that will be washed regularly. It offers good colour stability and durability, which is useful for children’s clothing, sports tops and workwear. Rayon creates a glossy finish but may need gentler laundering. Match the bobbin thread to the design instructions and check that the bobbin case is clean.

Reduce the embroidery speed if the machine allows it. A moderate speed gives the fabric and stabiliser more time to move together and can reduce thread breaks. Use the machine’s recommended embroidery foot, ensure the hoop can move freely and keep the garment’s unused fabric away from the needle area so it does not catch underneath.

Thread tension may need a small adjustment, but avoid changing several settings at once. Stitch a sample using the same fabric, stabiliser, needle and thread combination. Examine the front for puckering and the back for loose loops, bobbin show-through or excessive thread pull before starting the final garment.

Hoop, stitch and remove the garment carefully

Mark the centre and orientation of the design with a removable fabric pen. On a T-shirt, measure from the shoulder seams and neckline rather than relying on the garment’s apparent centre. A design can look crooked if the knit is slightly twisted, so lay the garment flat and compare both side seams before fixing the hoop position.

Keep the stabiliser large enough to support the entire design area. If a garment is difficult to hoop, float the stabiliser beneath the hoop and secure the fabric with temporary adhesive, clips or a few hand basting stitches outside the stitching field. This is often more comfortable for small children’s garments and narrow sleeves.

Watch the first few minutes of stitching. If the fabric begins to ripple, stop the machine and investigate rather than allowing the full design to finish. Check whether the hoop has loosened, whether the garment is caught under the hoop, or whether the design is too dense for the chosen stabiliser.

When the embroidery is complete, remove the garment from the hoop without pulling the fabric. Trim a cut-away stabiliser close to the stitching, leaving a smooth margin of about 3 to 5 millimetres. Do not cut into the embroidery or stretch the stabiliser while trimming. For sensitive skin, cover the back with an embroidery backing or soft iron-on garment shield.

Finish and care for embroidered knitwear

Press the embroidered area from the wrong side over a folded towel or a thick pressing cloth. Avoid crushing the raised stitches with a hot iron. Follow the fabric care label, particularly for polyester athletic knit, wool blends and garments containing elastane. Excessive heat can damage stretch fibres or flatten the embroidery.

Wash the finished garment inside out on a gentle cycle with mild detergent. Avoid bleach unless both the garment and thread manufacturer permit it. Air drying is usually kinder than a hot dryer, especially for lightweight interlock and children’s clothing that may be washed frequently.

For Australian customers, consider how the garment will be used in local conditions. A sports shirt worn in Brisbane humidity needs secure stitching and colourfast thread, while a merino-blend layer used around Canberra or Hobart may need a softer backing against the skin. Swim-club, school and community-sport garments also benefit from compact designs that can withstand regular washing.

If you sell embroidered clothing at a weekend makers’ market in Sydney, Perth or Adelaide, include simple care instructions with each item. Customers are more likely to preserve the fabric and embroidery when they know to wash the garment inside out, avoid harsh chemicals and keep direct heat away from the stitched area.

A practical checklist for reliable results

Use this short checklist before stitching a design on double knit or interlock:

Wash and dry the fabric or garment first, following its care label, so later shrinkage does not distort the embroidery.
Match the stabiliser to the stretch: use cut-away support for most knits and add a water-soluble topping when the surface is soft or textured.
Choose a design with moderate density, limited large satin areas and a finished size suited to the garment.
Use a fresh embroidery needle, quality thread and a clean bobbin case before beginning the project.
Hoop the stabilised fabric flat without stretching it, and keep seams, hems and ribbing outside the embroidery field.
Sew a complete test sample with the same fabric, stabiliser, needle, thread and machine settings.
Trim the backing neatly, press from the reverse side and provide gentle washing instructions for the finished item.

Downloadable files from EMBMall can make the planning stage easier because you can browse by theme and select a design for a particular garment or occasion. Check the file format required by your embroidery machine before purchase, and review the design dimensions, stitch count and colour sequence. If a special logo or motif is not available in the catalogue, a custom embroidery design service may help create a file suited to your chosen knit and hoop size.

A successful first project does not need to be elaborate. Select a medium-weight interlock, a small open design and a cut-away stabiliser, then stitch a sample before touching the finished garment. For the next step, prepare a 20-centimetre fabric test square and run one selected EMBMall design through it using the exact needle, stabiliser and thread combination planned for the final piece.