Easy Ivory Moth Open-Back Top: Perfect Summer Crochet Pattern

Yarn sits in a neat pile on the table, the ivory mercerized cotton catching the light. Your hook is already in hand, hovering over the first chain. The project is just beginning to take shape, and there is a quiet excitement in the air as you prepare to build this intricate piece. The Ivory Moth Open-Back Top is not just a garment; it is a wearable work of art that transforms simple stitches into a stunning summer statement.

Why This Project Works

What makes this design truly special is its modular construction. While the finished piece looks like a complex, high-end boutique find, the pattern breaks the moth down into manageable, separate components. You work the dense thorax, the four lace wings, and the side panels individually before joining them. This approach makes an advanced-looking project accessible to intermediate crocheters. The contrast between the dense, structured body and the airy, openwork wings creates a beautiful visual balance. Plus, the pale sage accents on the eyespots and wing outlines add a subtle, sophisticated touch that elevates the ivory base.

Project Overview

This pattern creates a size-inclusive, open-back halter top featuring a large luna moth motif spanning the upper back. The design includes a dense central thorax, four openwork wings with trailing tails, and separate side panels for coverage. It is finished with neck ties and decorative antennae.

Materials

• Main Yarn: Fine mercerized cotton in sport or light DK weight. Approximately 250 to 430 yards (230 to 395 meters) in ivory, depending on size.
• Contrast Yarn: Same weight cotton in pale sage. Approximately 30 to 55 yards (27 to 50 meters) for edging and eyespots.
• Hooks: 3.0 mm for lace sections; 2.75 mm to 3.0 mm for denser side panels.
• Notions: 6 locking stitch markers, tapestry needle, scissors, rustproof pins, blocking mat, and measuring tape.
• Optional: Clear elastic thread or narrow cotton tape for reinforcing side band joins.

Gauge and Finished Size

Gauge

• Dense fabric: 20 half double crochet (hdc) x 15 rows = 4 inches / 10 cm after blocking.
• Openwork: One 5-dc fan plus adjacent chain space = approximately 1.5 inches / 3.8 cm wide.

The exact openwork row gauge is less critical than matching the blocking dimensions. Use a hook that creates firm, tidy stitches without making the lace stiff.

Finished Sizes

Choose a size with 0 to 2 inches (0 to 5 cm) of negative ease for the best fit. For fuller busts, keep the moth span based on your back width and add width to the side panels instead of enlarging the central motif.

• XS: Bust 30-32 inches, Side panel width 4.5 inches, Moth span 15 inches, Top length 12.5 inches
• S: Bust 33-35 inches, Side panel width 5.0 inches, Moth span 16 inches, Top length 13 inches
• M: Bust 36-38 inches, Side panel width 5.5 inches, Moth span 17 inches, Top length 13.5 inches
• L: Bust 39-42 inches, Side panel width 6.25 inches, Moth span 18.5 inches, Top length 14 inches
• XL: Bust 43-46 inches, Side panel width 7.0 inches, Moth span 20 inches, Top length 14.5 inches
• 2XL: Bust 47-50 inches, Side panel width 7.75 inches, Moth span 21.5 inches, Top length 15 inches

Abbreviations

• beg = beginning
• ch = chain
• ch-sp = chain space
• dc = double crochet (yarn over, insert hook, pull up loop, yarn over and pull through 2 loops twice)
• hdc = half double crochet (yarn over, insert hook, pull up loop, yarn over and pull through all 3 loops)
• sc = single crochet (insert hook, pull up loop, yarn over and pull through both loops)
• sl st = slip stitch
• st(s) = stitch(es)
• tr = treble crochet
• dtr = double treble crochet
• RS = right side
• WS = wrong side
• rep = repeat
• sk = skip
• inc = increase

Special Stitches

• Fan: 5 dc in indicated space
• Small fan: 3 dc in indicated space
• Picot: ch 3, sl st in first ch
• Long-loop: ch 7-11 as specified, anchored with sc

Pattern Notes

This design is intentionally modular. The exact number of openwork repeats can be adjusted as long as the left and right sides remain mirrored and the blocked dimensions are respected. Always fit the garment before adding the final edging, because edging can reduce stretch slightly. For best visual balance, keep the upper wings broad, the lower wings slightly smaller, and the tails narrow. The dense thorax should remain centered on the spine.

Pattern Instructions

Central Thorax and Abdomen

This dense section forms the backbone of your moth and anchors all four wings.

• Row 1: With ivory, ch 9. Hdc in 2nd ch from hook and across. (8 hdc)
• Rows 2-4: Ch 1, turn. Hdc across. On Row 4, place a marker at each side for upper wing attachment.
• Rows 5-8: Ch 1, turn. Hdc2tog at both ends every other row until 4 sts remain. This narrows the upper thorax.
• Rows 9-12: Increase back to 6 sts by working 2 hdc in first and last st on Rows 9 and 11. Place markers at both sides of Row 11 for lower wing attachment.
• Rows 13-20: Continue in hdc, decreasing 1 st at one end every 2 rows until 3 sts remain. This forms the tapered abdomen.
• Row 21: Hdc3tog. Fasten off. Block to approximately 5.5 to 7 inches long depending on your size.
• Body edging: Join ivory at top edge. Sc evenly around, working 2 sc in lower tip. Fasten off.

Size note: For XL to 2XL, add 2 to 4 straight hdc rows through the middle of the thorax before beginning the abdomen taper.

Upper Wings (Make 2 Mirrored)

Each upper wing is worked outward from the thorax in widening openwork rows. Make the left wing first. For the right wing, reverse all edge placements so the outer scalloped edge mirrors the first.

• Foundation: Join ivory at the upper side marker of the thorax. Ch 7, sc into the next side stitch/row-end down the thorax; ch 9, sc 1 row lower; ch 11, sc 1 row lower. Turn. These three long loops become the main ribs.
• Row 1: Work into the three loops: (small fan in first loop, ch 3), (fan in second loop, ch 4), (fan in third loop). End with sc at lower attachment point.
• Row 2: Ch 5, turn. In each fan center work (dc, ch 2, dc); ch 4 between fan centers. At outer edge add ch 5 before turning back toward thorax.
• Row 3: Work a fan into each ch-2 space. Between fans make ch 3, sc around the ch-4 bridge, ch 3. At outer edge work 7 dc in the outer ch-5 space.
• Rows 4-6: Continue the same logic, increasing one open chain window at the outer edge on each row. Keep the thorax edge stable and allow all extra width to grow toward the shoulder.
• Row 7 (upper arc): Across the outer half only, alternate [tr, ch 2] and [dtr, ch 3] into successive spaces, then return to tr and dc toward the thorax. This creates the high rounded shoulder arc.
• Rows 8-9: Fill the tall-stitch ribs with fans and open ch-3/ch-4 windows. Stop when the wing reaches the target half-span from the center back.
• Final ivory edge: Sc along the outer wing curve, then work [sc, ch 3, sc] in every second or third space for soft scallops. Do not edge the thorax join yet.

Pale Sage Wing Outline

With RS facing, surface sl st or crochet a narrow line just inside the outer ivory scallop. Keep the sage line flat and relaxed. If it draws in, use a hook 0.25 to 0.5 mm larger.

Oval Eyespot (Make 2)

These little details really make the moth come alive.

• Rnd 1: With sage, ch 6. Sc in 2nd ch, hdc in next, dc in next 2, 5 dc in last ch; working along opposite side of foundation ch: dc in next 2, hdc in next, sc in last; join.
• Rnd 2: Ch 1. Sc around, working 2 sc in each of the three end stitches at both ends to maintain an oval. Join and fasten off.
• Attach: Sew one eyespot inside each upper wing approximately one-third of the way in from the outer edge. Tack through multiple points without closing the open chain windows.

Lower Wings and Luna Tails (Make 2 Mirrored)

• Foundation: Join ivory at the lower wing marker beside the thorax. Ch 9, sc 1 row lower; ch 11, sc 1 row lower; ch 13, sc near the start of the abdomen. Turn.
• Row 1: Small fan in first loop, ch 4, fan in second loop, ch 4, 7 dc in third loop.
• Row 2: Ch 5, turn. Work (dc, ch 2, dc) in each fan center. Across the outermost 7-dc group work [dc, ch 2] in every other dc to create extra spread.
• Rows 3-5: Alternate fan rows and rib rows as for upper wings. Increase only along the lower outside edge so the wing sweeps outward while remaining attached cleanly to the thorax.
• Tail setup: At the lowest outside point, ch 18 (20, 22, 24, 26, 28) for XS (S, M, L, XL, 2XL). Turn and sl st in first 4 ch, sc in next 4, hdc in next 4, dc in remaining ch. Join back into the wing edge.
• Tail shaping row: Work down the tail with sc along the inside curve, 3 sc in the tip, then hdc/dc along the outer side. Add one ch-3 picot near the tip if desired.
• Wing finishing: Sc around the lower wing and tail. Along the broad wing edge, work soft ivory scallops [sc, ch 3, sc] every 2-3 spaces. Keep the long tail edge simpler so it stays narrow.
• Sage outline: Surface sl st just inside the outer edge, continuing down both sides of the tail. Ease the contrast yarn through the curve without tightening.

Blocking target: Each lower wing should curve out from the center, then turn gently inward at the tail. Pin the final 2-3 inches of each tail into a shallow crescent rather than a straight line.

Side Panels (Make 2)

The side panels provide coverage and fit. Work them in dense hdc from the underarm downward.

• Foundation: Ch enough stitches to equal the side panel width for your size at 20 sts = 4 in / 10 cm. Approximate starting counts: XS 23, S 25, M 28, L 32, XL 35, 2XL 39. Add 1 turning ch.
• Rows 1-4: Hdc across. Ch 1 and turn each row.
• Waist shaping: Decrease 1 st at the back edge every 4th row, 2-4 times depending on size. Continue straight until panel reaches 8.5 (9, 9.5, 10, 10.5, 11) inches tall.
• Upper shaping: Over the final 2 inches, decrease 1 st at the back edge every other row to angle the panel toward the lower part of the upper wing.
• Edging: Sc around all four sides. Along the back edge, place a ch-2 loop every 0.75-1 inch for later joining. Fasten off.

Assembly

1. Block first: Wet block the thorax, four wings, side panels, and eyespots before assembly. Pin the moth to your paper template so the two sides match.
2. Join upper wings: With ivory and RS facing, whipstitch or slip-stitch the inner edges of both upper wings to the marked thorax section. Keep the attachment flexible.
3. Join lower wings: Attach the lower wings to the lower thorax/upper abdomen markers. The top of each lower wing should nest just beneath the upper wing without a gap.
4. Attach side panels: Position each panel so the top back corner sits near the base of the upper wing and the lower back corner meets the outside of the lower wing. Lace or crochet between the panel loops and wing edge using ch-2 to ch-4 bridges. Try on frequently.
5. Reinforce: Where the side panel meets the wing, work a second pass of sl sts or hand-sewn cotton stitches through the connection points. This prevents the lace from stretching under tension.
6. Check symmetry: Lay the top flat and compare the two sides from center back to each underarm. Adjust one or two bridge lengths if needed before weaving in ends.
7. Tie 1: Join ivory at the top outer corner of the left upper wing. Ch 75-95 depending on preferred tie length. Sl st back along the chain for a firm cord. Fasten off.
8. Tie 2: Repeat on the right upper wing.
9. Optional softer cord: Instead of slip-stitch cord, make a 2-stitch Romanian cord to the desired length.
10. Finish: Steam or wet block the ties straight, then tie behind the neck in a bow. The upper wing tips should sit flat rather than pulling upward.
11. Antennae:
    • Base: Join ivory at the top center of the thorax. Ch 11.
    • Feathering: Working back toward the body, repeat: sl st in next ch, ch 3, sl st in same ch, then sl st in next ch. Make the feather branches on only one side of the chain.
    • Second antenna: Repeat from the adjacent thorax stitch, angling outward in the opposite direction.
    • Shape: Lightly block each antenna into a shallow curve. For a very crisp shape, sew the antenna to the upper wing at one discreet point near its base only.
12. Front and Underarm Finishing: The photographed garment focuses on the back motif, so you can customize the front. The easiest matching front is a simple dense crop panel: work a rectangle or shallow V in hdc to your bust measurement, then seam or crochet it to the front edges of the two side panels. For a halter-style front, decrease toward the neckline over the final 3-4 inches and continue the neck ties from the upper corners. Design tip: If you want the back to remain the focal point, keep the front plain and use the same ivory yarn without sage embellishment.
13. Perimeter border: With ivory, sc evenly around any exposed garment edges. Work 2 sc in convex corners and sc2tog in tight concave corners.
14. Scallops: Along selected wing arcs only, add [sc, ch 3, sc] every 2-3 spaces. Avoid heavy scalloping on side panels and tail tips.
15. Sage detail: Add a single fine sage surface line inside the upper and lower wing borders if not already completed.

Tips

• Pro tip: Before beginning, trace a simple paper template of your intended moth silhouette at the finished span for your size. Divide the template vertically so both sides stay symmetrical. Pin your pieces to this template during blocking for perfect results.
• Fit Adjustment: For fuller busts, keep the moth span based on your back width and add width to the side panels instead of enlarging the central motif. This keeps the moth looking proportional.
• Modular Construction: Do not let the “advanced” label scare you off though! The construction is modular, meaning you work each piece separately before joining them together. This makes it much more manageable than trying to work the entire motif in one go.
• Design Tip: If you want the back to remain the focal point, keep the front plain and use the same ivory yarn without sage embellishment.

Care Instructions

Hand wash or use a delicate cycle in a mesh bag with cool water. Reshape while damp and dry flat. Avoid hanging the wet garment, because the moth tails and openwork may lengthen under their own weight. Store folded.

FAQs

Is this pattern difficult for a beginner?

This pattern is rated intermediate to advanced. It requires comfort with basic stitches, working in the round, and following multi-step construction. However, the modular design makes it manageable if you have made a few garments before.

How do I adjust the fit for a larger bust?

For fuller busts, keep the moth span based on your back width and add width to the side panels instead of enlarging the central motif. This keeps the moth looking proportional.

Can I make the front of the top different?

Yes. The easiest matching front is a simple dense crop panel in hdc. You can also create a halter-style front by decreasing toward the neckline over the final 3-4 inches.

What yarn is best for this project?

Use fine mercerized cotton in sport or light DK weight. The mercerized finish helps the lace hold its shape and gives a nice sheen.

How should I block the moth tails?

Pin the final 2-3 inches of each tail into a shallow crescent rather than a straight line to mimic the natural curve of a luna moth.

Do I need to use the sage yarn?

The sage yarn is used for the eyespots and wing outlines. If you prefer a monochromatic look, you can skip the sage and keep the front plain, but the contrast helps define the moth silhouette.