How to Add Lining to a Crochet Bikini: 3 Easy Ways and Best Fabrics

Have you ever spent hours crafting the perfect crochet swimwear, only to realize it becomes completely see-through the second it touches water? You are definitely not alone! I have been there, and let me tell you, running out of the ocean with a sagging, translucent bikini top is not the summer vibe we are going for!

To make your handmade pieces wearable, secure, and beach-ready, you absolutely must learn how to add lining to a crochet bikini. According to a survey of fiber artists, over 85% of crocheters agree that unlined crochet swimwear stretches out, loses its shape, and fails to provide adequate coverage when wet. Adding a lining is the ultimate game-changer! It preserves your stitches, keeps everything opaque, and ensures your gorgeous work lasts for seasons.

Let’s dive into exactly how you can easily line your bikini bottoms and tops using three simple DIY methods and the absolute best fabrics available.

Materials Needed

Fabric

Here are the top 3 fabric choices for lining handmade swimwear:

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Before we start, gather these essential sewing and crochet tools:

• Your finished crochet bikini top and bottoms
• High-quality swim lining fabric (Nylon-Spandex or Swim Lining)
• Sew-in or removable swimsuit cup pads
• A sharp rotary cutter or fabric shears
• Sewing pins or fabric clips
• Hand sewing needles (choose ballpoint or stretch needles)
• Your crochet hook and a small amount of matching yarn (for Option 3)
• A sharp yarn needle or darning needle

Sewing the Crochet Bikini Lining

Option 1: How to Manually Sew Fabric Lining

This is the most traditional method. It is perfect for both bikini tops and bottoms. By hand-stitching a custom-cut piece of stretch fabric directly to the inside of your crochet piece, you create a permanent, professional-grade barrier.

1.Trace and cut your pattern: Allow 1/2 inch extra.

Lay your crochet bikini piece flat on top of your swim lining fabric. Using a fabric marker, trace the shape of the crochet piece. Cut out the fabric, leaving a 1/4-inch (0.5 cm) seam allowance all the way around the edge.

2.Fold and pin the edges: Hide the raw edges.

Fold the 1/2-inch raw edge of the fabric inward (toward the side that will touch the crochet, not your skin) so that the fold matches the exact shape of your bikini. Pin or clip this folded edge securely to the wrong side of your crochet bikini.

3.Hand sew using a whip stitch:Keep stitches loose and flexible.

Thread your hand-sewing needle with matching polyester thread. Sew the folded fabric edge to the inner loops of your crochet stitches using a whip stitch or a blind hem stitch. Do not pull the thread too tight! The lining needs to stretch along with the crochet.

Option 2: How to Manually Sew Pads Directly Into the Top

If you want shaping, support, and nipple coverage without lining the entire garment with fabric, you can sew pre-shaped foam swimsuit cups directly into the bikini top.

Step 1: Position the Pads

Slip your crochet bikini top on (or place it on a dress form) to find the perfect placement for the foam inserts. Use safety pins to pin the pads securely to the inside of the cups.

Step 2: Prep Your Needle and Thread

Thread a sharp hand-sewing needle with a double strand of polyester thread matching your yarn. Tie a secure knot at the end.

Step 3: Sew with a Zig zag Stitch

Turn the top inside out. Carefully sew around the entire perimeter of the foam pad, securing it to the back loops of your crochet stitches. Be incredibly careful not to let your needle pierce through to the front of the bikini. Keep your stitches spaced about 1/4 inch apart. Knot your thread securely at the end.

Option 3: Crochet Directly onto the Pads (No-Sew Hack!)

This is a favorite hack among crocheters who absolutely hate hand-sewing with traditional needle and thread. By prepping the foam pad with tiny holes, you can crochet a border directly onto the pad, and then slip-stitch or sew it to your bikini top using your yarn!

Step 1: Punch Holes in the Pad

Take your foam swimsuit pads. Using a sharp yarn needle or a leather punch, poke small holes around the entire outer border of the foam cup. Space these holes about 1/4 inch (6 mm) apart and about 1/4 inch in from the edge.

Step 2: Crochet a Border

Using your matching yarn and a small crochet hook (usually a 1.25mm to 1.5mm hook), insert your hook into one of the punched holes. Pull up a loop of yarn and work single crochet (SC) stitches with a CH in the middle all the way around the edge of the pad. Work 1 or 2 single crochets into each hole to ensure the edge lies flat without puckering.

Step 3: Slip Stitch the Pad to the Bikini Top

Now that your pad has a beautiful crochet border, place it inside your bikini cup. Using your crochet hook, simply slip stitch the crocheted border of the pad directly to the inner stitches of your bikini top! This creates a flawless, perfectly blended, and completely secure connection.

Watch the Full Tutorial Here!

Frequently Asked Questions (FAQ)

Do you have to line a crochet bikini?

Yes, you absolutely should line a crochet bikini if you plan to wear it in the water. Crochet fabric is naturally full of tiny gaps. When cotton or acrylic yarn gets wet, it absorbs water, stretches significantly, and becomes see-through. A proper lining provides essential coverage, protects your modesty, and helps the swimsuit retain its shape and elasticity over time.

What is the best stitch for a crochet bikini?

The best stitch for a crochet bikini is the Single Crochet (SC) or the Double Crochet (DC) worked tightly. Working in the back loops only (BLO) can also provide a beautiful, stretchy texture. Always use a hook size slightly smaller than what the yarn label recommends. This keeps your stitches dense, minimizes holes, and makes the lining process much easier.

Can you swim in a cotton crochet bikini?

You can swim in a cotton crochet bikini, provided you use the right yarn and line it properly! Look for 100% mercerized cotton yarn or cotton-blend yarns with a bit of elastic/polyester content. Mercerized cotton is treated to absorb less water and stretch less than standard kitchen cotton. When paired with a high-quality synthetic lining, your cotton crochet bikini will perform beautifully in the pool or ocean.

See my blog post about Best Yarn for Crochet Bikinis

Best Fabrics for Lining a Crochet Bikini

Choosing the right lining material is half the battle. Regular cotton fabric will absorb water, grow heavy, and sag. Instead, you need a high-quality, synthetic four-way stretch fabric.

Summary and Closing Thoughts

Adding a lining to your crochet bikini is the absolute best way to turn a beautiful DIY craft into a functional, wearable, and durable piece of swimwear. Whether you choose to manually sew stretch nylon fabric, sew in foam pads for shaping, or use the clever crochet-on-the-pad method, your bikini will look incredibly professional and stand up to water beautifully.

Make sure to take your time, keep your hand-sewing stitches loose enough to stretch, and always opt for synthetic fabrics that dry quickly. Happy crafting, and enjoy rocking your gorgeous, completely opaque handmade swimwear at the beach!