You’ve just landed in paradise—palm trees swaying, turquoise water beckoning, and the promise of sun-soaked relaxation ahead. But as you unzip your suitcase, that excitement deflates faster than a cheap inflatable. Your carefully packed swimwear is a crumpled mess of creases and folds that no amount of shaking seems to fix. This all-too-familiar vacation nightmare has plagued travelers for decades, but modern textile innovation has finally delivered a solution. Wrinkle-resistant swimwear isn’t just a marketing gimmick; it’s a game-changing fusion of fabric technology and intelligent design that ensures you look as fresh as your destination.
As frequent travelers and textile experts have discovered, the secret to effortless vacation style lies not in how you pack, but in what you’re packing. Today’s advanced swimwear combines quick-dry performance with remarkable resilience, allowing you to roll, fold, or cram your suits into the most overstuffed carry-on without worrying about unsightly lines or misshapen cups. This comprehensive guide dives deep into the world of travel-friendly swimwear, exploring the science, features, and strategies that will revolutionize how you approach vacation packing forever.
Top 10 Wrinkle-Resistant Swimwear for Vacation Suitcases
Detailed Product Reviews
1. Bsubseach Women Swimsuit Coverup Shirt Dress Button Down Bathing Suit Cover Up Beachwear Khaki XL
Overview:
The Bsubseach Coverup Shirt Dress reimagines beachwear as a true wardrobe multitasker. This khaki button-down piece functions equally well as a swimsuit cover-up and a casual shirt dress, bridging the gap between resort wear and everyday fashion. Its classic shirt silhouette with a lapel collar and chest pocket offers a polished aesthetic that transitions seamlessly from sand to street.
What Makes It Stand Out:
The versatility is unmatched—you can layer it over swimwear or pair it with shorts, skirts, or pants for a complete outfit. The curved hem adds a feminine touch, while the lightweight fabric blend ensures comfort during hot summer days. With sizes ranging from XS to 3XL, it accommodates more body types than most competitors, making it genuinely inclusive.
Value for Money:
At $27.35, this cover-up delivers exceptional value. You’re essentially getting two garments in one: a beach cover-up and a casual shirt dress. Comparable versatile pieces often cost $35-40, making this a budget-friendly choice without sacrificing style or functionality.
Strengths and Weaknesses:
Strengths include breathable fabric, true versatility, extensive size range, and easy styling options. The button-down design offers adjustable coverage. Weaknesses: those between sizes are advised to size down for a fitted look, which might not suit everyone seeking a relaxed beach vibe. The fabric blend isn’t specified beyond “soft and lightweight,” leaving durability questions.
Bottom Line:
Perfect for travelers and minimalists who want maximum versatility. If you’re looking for one piece that works overtime in your summer wardrobe, this cover-up shirt dress is a smart, stylish investment that punches above its price point.
2. Spicy Sandia Beach Cover Ups for Women Swimsuit Coverup Bathing Suit Swim Swimwear Dress Summer Vacation Outfits Navy L
Overview:
The Spicy Sandia Beach Cover Up is engineered for the serious beach traveler who demands performance from their resort wear. This navy dress tackles common vacation frustrations head-on with innovative fabric technology that eliminates wrinkles and accelerates drying time, making it a practical choice for active beach days.
What Makes It Stand Out:
The Crease-Crusher fabric technology is revolutionary—shake it out straight from your luggage and wear within seconds. It dries five times faster than cotton, transforming from ocean-drenched to beach-bar-ready while you walk. The non-sheer polyester-spandex blend is both breathable and opaque, blocking swimsuit lines while resisting sand abrasion, saltwater corrosion, and UV damage even after 20+ beach trips.
Value for Money:
At $26.99, you’re paying for advanced textile engineering typically found in premium activewear. Standard cover-ups lack these performance features and often require replacement after one season. This piece’s durability and travel-friendly properties make it a cost-per-wear champion.
Strengths and Weaknesses:
Strengths include unbeatable wrinkle resistance, lightning-quick drying, durable non-sheer fabric, and machine-washable convenience. It rolls into a fist-sized pouch for easy packing. Weaknesses: the loose, straight-cut silhouette may feel too oversized for those preferring defined shapes. The polyester-based fabric, while practical, lacks the natural feel of cotton or rayon.
Bottom Line:
Ideal for frequent travelers and beach enthusiasts who prioritize function alongside fashion. If you’ve ever been frustrated by wrinkled, clingy, or sheer cover-ups, this technical piece solves those problems brilliantly at a surprisingly accessible price.
3. Sampeel Spring Dresses for Women 2025 Casual Long Maxi Dress 2025 Sundresses Beach Vacation Swimsuit Coverup Army Green S
Overview:
The Sampeel Maxi Dress elevates the cover-up into a legitimate fashion statement. This army green sundress combines beach casualness with sophisticated styling, featuring a flattering V-neck, side slit, and practical pockets. Designed for 2025, it transitions effortlessly from poolside cover-up to dinner date attire.
What Makes It Stand Out:
The inclusion of side pockets sets it apart from flimsy cover-ups, offering genuine functionality. The side slit provides alluring movement while maintaining elegance. Its versatility is remarkable—wear it with flip-flops for the beach, dress it up with jewelry for evening events, or layer with a denim jacket for casual outings. The fabric blend (60% polyester, 35% rayon, 5% spandex for solids) balances softness with structure.
Value for Money:
At $25.99, this maxi dress is a steal. Comparable maxi dresses with pockets and quality fabric typically start at $40. The ability to function as swimwear cover-up, casual day dress, and even office-appropriate attire (with the right accessories) delivers triple-duty value.
Strengths and Weaknesses:
Strengths include the flattering V-neck design, functional pockets, comfortable lightweight fabric, and true versatility across occasions. The side slit adds style without compromising coverage. Weaknesses: sizing runs by US dress sizes, which can be inconsistent across brands. Fabric composition differs between solid and floral prints, requiring careful reading before purchase.
Bottom Line:
An exceptional choice for vacationers seeking one dress that does everything. If you value pockets, comfort, and multi-occasion versatility in your summer wardrobe, this maxi delivers premium features at a budget-friendly price point.
4. RipSkirt Hawaii Length 2 - Wrap Skirt for Women - Quick Dry Swim Cover-Up with Side Pocket - Lightweight for Beach and Travel and Casual Wear (Maui Moonlight, XXL 20-22)
Overview:
The RipSkirt Hawaii Length 2 revolutionizes beach cover-ups with its ingenious wrap design and premium performance fabric. This Maui Moonlight print skirt prioritizes convenience and style, featuring a secure Velcro closure that eliminates the struggle of pulling on skirts over damp skin. It’s engineered for women who demand both function and fashion.
What Makes It Stand Out:
The quick-wrap Velcro system is a genuine game-changer for beach transitions, especially with wet, sandy feet or limited mobility. The custom fabric repels water, dries exceptionally fast, and resists wrinkling while flattering diverse body shapes. Phone-sized hip pockets add practical storage rarely found in cover-ups. The lightweight fabric folds compactly, making it ideal for travel.
Value for Money:
At $55, this is a premium investment. However, you’re paying for patented design innovation and high-performance fabric that outlasts cheaper alternatives. For frequent beach-goers, travelers, or those with mobility challenges, the convenience factor alone justifies the cost. Comparable quality performance skirts in the activewear market often exceed $70.
Strengths and Weaknesses:
Strengths include effortless on/off functionality, quick-dry wrinkle-resistant fabric, flattering fit across sizes, practical pockets, and compact packability. The wrap design accommodates fluctuating sizes comfortably. Weaknesses: the premium price point may deter occasional beach visitors. Velcro closures can lose effectiveness over time with heavy use and require careful laundering.
Bottom Line:
A worthwhile splurge for those who prioritize convenience and quality. If you frequently transition from beach to casual settings or struggle with traditional cover-ups, this innovative wrap skirt will become your most-valued summer piece despite the higher price tag.
5. Sarong Wrap Cover Up Long with Easy Wearing Built in Ties – Wrinkle Resistant Beach Sarong, Black
Overview:
This Sarong Wrap Cover Up delivers the timeless elegance of a classic beach sarong with modern convenience features. The black chiffon piece measures 35x48 inches and features built-in ties that eliminate the learning curve of traditional sarong styling, offering effortless sophistication for beach and poolside wear.
What Makes It Stand Out:
The integrated ties are brilliantly simple—just knot and go without fumbling with separate strings or complicated wrapping techniques. The premium chiffon fabric provides a slight see-through effect that’s intentionally alluring while remaining flattering across body types. Its wrinkle-resistant polyester composition ensures it emerges from your suitcase ready to wear, making it ideal for destination vacations.
Value for Money:
At $29.99, this sarong sits in the sweet spot for quality cover-ups. Authentic chiffon pieces often cost $40+, while cheaper versions use flimsy fabric that pills or frays. The built-in ties add value by simplifying wear, and the durability ensures seasons of use.
Strengths and Weaknesses:
Strengths include easy tie construction, travel-friendly wrinkle resistance, lightweight breathable fabric, and versatile styling options (waist wrap or bubble tie dress). The classic black color pairs with any swimsuit. Weaknesses: the “fits up to size 14” range excludes plus-size women. The slight sheerness, while intentional, may not suit those wanting full coverage. Manual tying still requires some practice despite built-in ties.
Bottom Line:
Perfect for travelers who appreciate classic beach glamour without the fuss. If you love the versatility of a sarong but want simplified styling and travel-friendly fabric, this piece delivers elegant functionality at a reasonable price point.
Why Wrinkle-Resistance Matters for Vacation Swimwear
Vacation time is precious, and nothing wastes those golden hours quite like hunting down a steamer or attempting to smooth out stubborn fabric creases in a humid hotel bathroom. Traditional swimwear, with its delicate construction and performance-focused fabrics, was never designed with packability in mind. The result? Straps that twist permanently, padded cups that fold in on themselves, and edges that develop memory lines from being pressed under heavier items.
Wrinkle-resistant swimwear addresses these pain points through engineered fibers and strategic construction. Unlike your everyday clothing, swimwear faces unique challenges: it must maintain its shape when wet, dry quickly, resist chlorine and salt damage, and emerge from your suitcase looking resort-ready. The technology behind these garments represents a sophisticated evolution in textile manufacturing, where every thread serves multiple purposes. For the savvy traveler, investing in wrinkle-resistant pieces means less time fussing with your wardrobe and more time actually enjoying your hard-earned getaway.
The Science Behind Wrinkle-Resistant Fabrics
Understanding what makes swimwear truly wrinkle-resistant requires peeling back the layers of fabric engineering. The magic happens at the molecular level, where polymer structures and weave patterns work together to create memory and recovery properties that natural fibers simply cannot match.
Understanding Fabric Weaves and Constructions
The foundation of wrinkle resistance lies in how threads are interlaced. Knit constructions, particularly weft-knit styles like tricot, dominate high-performance swimwear because they create inherent stretch and recovery. Unlike woven fabrics where threads cross at rigid right angles, knit constructions loop together, allowing fibers to return to their original position after being compressed in a suitcase. Look for terms like “circular knit” or “warp knit” in product descriptions—these indicate a tighter, more resilient structure that bounces back from pressure.
Density also plays a crucial role. Premium swimwear features a higher gauge knit, meaning more threads per inch. This creates a smoother surface that’s less prone to showing fold marks and provides better compression recovery. Think of it like the difference between a loosely woven basket and a tightly coiled spring—the tighter construction springs back when released.
The Role of Synthetic Fibers in Wrinkle Prevention
Natural fibers like cotton might feel luxurious, but they’re structurally doomed in swimwear applications. They absorb water, lose shape when wet, and retain creases from packing. Synthetic fibers, on the other hand, are engineered for resilience. Their thermoplastic nature means they can be heat-set during manufacturing to “remember” their shape. When your suitcase compresses these fibers, they naturally want to return to that original, smooth configuration.
The molecular structure of these polymers includes crystalline regions that act like tiny springs, providing dimensional stability. This is why a quality synthetic swimsuit can be balled up in your bag for hours yet smooth out within minutes of putting it on—your body heat actually helps activate the fiber’s shape-memory properties.
Key Features to Look for in Travel-Friendly Swimwear
Beyond basic fabric composition, several specific features elevate a swimsuit from merely functional to truly travel-optimized. These elements work synergistically to ensure your swimwear performs as well in your luggage as it does in the water.
Quick-Dry Technology: The Perfect Companion
The relationship between wrinkle resistance and drying speed is inseparable. Swimwear that retains moisture for extended periods becomes heavier and more prone to developing set-in creases. Modern quick-dry technology employs hydrophobic fiber treatments and moisture-wicking constructions that move water away from the fabric surface. This means your suit dries before wrinkles can become permanent, whether you’re hanging it to dry post-rinse or unpacking it after a long flight.
Look for descriptions mentioning “water-repellent coatings” or “moisture management systems.” These aren’t just buzzwords—they indicate chemical finishes applied at the fiber level that reduce water absorption to less than 1% of the fabric’s weight, compared to 7-10% in standard swimwear.
UV Protection and Colorfastness
Nothing ruins a vacation look faster than faded, misshapen swimwear that looks like it’s been through a decade of summers. Premium wrinkle-resistant swimwear incorporates UV-inhibiting agents directly into the fiber matrix, preventing the photodegradation that weakens fabric structure and leads to permanent creasing. This same technology preserves color vibrancy, ensuring your suit looks as crisp on day seven as it did on day one.
Check for UPF (Ultraviolet Protection Factor) ratings of 50+ and terms like “solution-dyed” or “mass-dyed” fibers. These indicate the color is embedded during fiber production rather than added later, creating superior fade resistance and structural integrity.
Stretch Recovery and Shape Retention
The best wrinkle-resistant swimwear features multi-directional stretch with excellent recovery—meaning it can stretch significantly and return to its original dimensions without distortion. This property, often measured as “power stretch” or “4-way stretch,” ensures that even if your suit gets folded or rolled tightly, the fibers will bounce back rather than developing memory lines.
Pay attention to the elastane content (also known as spandex or Lycra). While 20% was once the standard, modern travel-optimized suits often contain 18-22% elastane blended with more resilient base fibers. Too much elastane can actually reduce recovery over time, while too little compromises the fit and comfort.
Fabric Blends That Fight Wrinkles
Not all synthetic blends are created equal when it comes to travel performance. Understanding the specific properties of each combination helps you make informed decisions that align with your vacation needs.
Nylon-Spandex Blends: The Gold Standard
The classic 80/20 nylon-spandex blend remains the benchmark for premium swimwear, and for good reason. Nylon offers exceptional strength-to-weight ratio, meaning it resists abrasion and tearing while remaining lightweight in your suitcase. Its smooth surface naturally resists creasing, and when combined with spandex, it creates a fabric that moves with your body while maintaining its shape.
Advanced versions of this blend incorporate texturized nylon yarns that increase surface area for faster drying and improved wrinkle recovery. These micro-textured surfaces create tiny air pockets that prevent fabric layers from sticking together and forming creases during compression.
Polyester Innovations
Polyester has undergone a renaissance in swimwear manufacturing, shedding its reputation as a cheap alternative to nylon. Modern polyesters are engineered at the polymer level for specific performance characteristics. PBT (polybutylene terephthalate) polyester, for instance, offers natural stretch and recovery properties that rival spandex blends while being more resistant to chlorine and sunscreen damage.
For travelers, polyester’s key advantage is its superior wrinkle resistance. The fiber’s higher crystalline structure makes it more dimensionally stable than nylon, meaning it resists deformation even under significant pressure. Look for “high-twist” polyester yarns, which add crimp and texture that enhance both stretch and recovery.
Emerging Eco-Friendly Options
Sustainability doesn’t have to mean sacrificing performance. Recycled nylon and polyester, made from discarded fishing nets and plastic bottles, now match or exceed the wrinkle resistance of virgin fibers. These materials undergo the same engineering processes, ensuring you don’t compromise on packability while reducing environmental impact.
Innovative brands are also experimenting with bio-based elastane alternatives derived from renewable resources. While still emerging, these options promise the same recovery properties as traditional spandex with a smaller carbon footprint—perfect for the eco-conscious traveler who values both performance and planet.
Packing Strategies for Wrinkle-Free Swimwear
Even the most resilient swimwear benefits from smart packing techniques. The way you position and protect your suits in your suitcase can mean the difference between ready-to-wear and slightly rumpled.
The Roll vs. Fold Debate
The rolling technique has become popular among travel experts for good reason—it minimizes sharp creases by creating gentle curves rather than harsh folds. For swimwear, roll each piece loosely, starting from the bottom and working upward. This method distributes pressure evenly and prevents the elastic bands from developing memory lines.
However, folding has its place, particularly for structured bikini tops with molded cups. In these cases, fold the cups into each other to maintain their shape, then fold the entire piece around a soft item like a pair of socks. This creates a buffer that prevents permanent indentation from other luggage contents.
Strategic Placement in Your Suitcase
Where you place your swimwear matters as much as how you pack it. The center of your suitcase experiences the most compression, so reserve that space for durable items like shoes and toiletries. Instead, tuck your rolled swimwear along the edges and corners where pressure is lighter.
Consider using the “bundle wrapping” method for extended trips: wrap your swimwear around a core of soft items, creating a protective cocoon. This technique is particularly effective for preventing hardware on bikini tops from pressing into fabric and creating dents. Always place swimwear in a breathable mesh bag rather than a sealed plastic one, which traps moisture and can lead to mildew and set-in wrinkles.
Caring for Your Swimwear on the Road
Proper maintenance during your vacation directly impacts wrinkle resistance. A few simple habits can preserve your suit’s structure and ensure it remains ready for spontaneous beach outings.
Rinse Protocols for Longevity
Chlorine, salt, and sunscreen are the trifecta of swimwear degradation. They break down fiber structure, reducing elasticity and making fabrics more prone to wrinkling. Always rinse your suit in fresh water immediately after swimming—even if you can’t do a full wash until later. This simple step prevents chemical buildup that weakens fibers and compromises their recovery properties.
Pack a small bottle of gentle detergent specifically formulated for delicates. These pH-balanced cleaners remove damaging residues without stripping away the fabric’s protective coatings. Never use hotel body wash or shampoo, as their harsh detergents can degrade the elastane content.
Drying Techniques in Humid Climates
Hanging your suit to dry seems straightforward, but improper technique can create new wrinkles. Never wring out your swimwear—this twists fibers and damages the elastic structure. Instead, gently press the suit between two towels to absorb excess water, then lay it flat on a fresh towel in a well-ventilated area.
If you’re dealing with high humidity, position a fan to create airflow or hang the suit near (but not directly on) the air conditioning vent. The goal is consistent air movement that prevents moisture from settling into fabric folds. Avoid direct sunlight, which can degrade fibers and fade colors, ironically making the fabric more prone to wrinkling over time.
Style Considerations That Impact Packability
Your swimwear’s aesthetic choices directly affect how well it travels. Certain design elements can either enhance or undermine wrinkle-resistant properties.
Hardware and Embellishments: Hidden Wrinkle Culprits
Metal rings, decorative buckles, and beading might elevate your beach look, but they create pressure points in your suitcase. These rigid elements press into surrounding fabric, leaving indentations that can be difficult to remove. Opt for designs that use bonded seams or molded details instead of attached hardware.
If you love embellished pieces, pack them with small pieces of foam or bubble wrap protecting the decorative elements. This prevents them from pressing into the suit’s main fabric and creating permanent impressions. Better yet, choose suits with laser-cut details or heat-pressed patterns—these add visual interest without compromising packability.
Print and Pattern Choices
Solid colors, particularly dark shades, show wrinkles more visibly than strategic prints. A textured jacquard pattern or a busy tropical print can camouflage minor creases that might otherwise be obvious on a plain black suit. However, be wary of large-scale prints with distinct geometric patterns, as any misalignment caused by stretching can be immediately noticeable.
Color placement also matters. Suits with color-blocking or strategic paneling often use different fabric tensions in each section, which can lead to uneven wrinkling. A more uniform construction ensures consistent recovery across the entire garment.
Debunking Common Myths About Wrinkle-Resistant Swimwear
Misinformation abounds in the world of performance fabrics. Let’s separate fact from fiction to ensure you’re making truly informed decisions.
Myth: Wrinkle-resistant means you can pack it any way you want. While these fabrics are remarkably forgiving, they’re not magic. Extreme compression for extended periods can still create memory lines, especially in padded or structured pieces. Smart packing remains essential.
Myth: Higher price always equals better wrinkle resistance. Price often reflects brand positioning rather than technical performance. A mid-range suit with a quality nylon-spandex blend and proper construction can outperform a luxury designer piece that prioritizes aesthetics over function. Focus on fabric specifications, not just price tags.
Myth: Wrinkle-resistant swimwear feels stiff or uncomfortable. Early performance fabrics did sacrifice softness for structure, but modern textile engineering has solved this. Today’s premium blends are indistinguishable from traditional swimwear in terms of comfort, yet far superior in travel performance.
Myth: You need special detergents to maintain the wrinkle-resistant properties. While harsh chemicals can degrade fibers over time, standard gentle detergents work perfectly fine. The key is avoiding bleach, fabric softeners, and high heat—not necessarily buying specialized products.
Expert Tips for Maximizing Suitcase Space
Smart travelers know that swimwear can actually help organize your luggage rather than just occupying space. Use these professional packing strategies to turn your suits into packing tools.
Layer bikini tops between delicate items like silk scarves or dress shirts—the smooth fabric acts as a protective barrier while maintaining its own shape. Stuff the cups of padded tops with socks or underwear to preserve their form and utilize otherwise wasted space. For one-piece suits, wrap them around shoes to keep the shoe shape and protect your suit from hardware abrasion.
Consider packing multiple bikini bottoms but fewer tops to maximize outfit combinations while minimizing bulk. A single quality top can pair with three different bottoms, creating variety without filling your suitcase. Store these smaller items in the corners of your luggage or inside packed hats to use every available inch efficiently.
Frequently Asked Questions
1. How long does wrinkle-resistant technology last in swimwear?
With proper care, the wrinkle-resistant properties should last the lifetime of the suit—typically 1-3 years with regular use. The key is avoiding chlorine and sunscreen buildup, which degrade the elastane content. Rinse immediately after each use and rotate between multiple suits on extended trips.
2. Can I iron wrinkle-resistant swimwear if creases do appear?
Never use a traditional iron directly on swimwear. The high heat melts synthetic fibers and destroys elasticity. If stubborn creases develop, hang the suit in a steamy bathroom or use a handheld garment steamer held at least 6 inches away. The gentle heat and moisture help fibers relax without damage.
3. Are there specific brands known for wrinkle-resistant swimwear?
While we don’t recommend specific brands, look for companies specializing in performance swimwear or travel apparel. These manufacturers typically invest in textile R&D and provide detailed fabric specifications. Avoid fast-fashion brands that prioritize trend over technical construction.
4. Does wrinkle-resistant swimwear cost more than regular swimwear?
Generally, yes—expect to pay 20-40% more for true wrinkle-resistant technology. However, the durability and versatility often make them more economical long-term. A $80 travel-friendly suit that lasts three seasons beats a $40 suit that needs replacement annually.
5. Can I pack wet wrinkle-resistant swimwear in my suitcase?
Even quick-dry suits should never be packed while wet. Trapped moisture leads to mildew, odor, and can set wrinkles permanently. If you must pack damp (like when rushing to the airport), place the suit in a breathable mesh bag with a silica gel packet and unpack it immediately upon arrival.
6. How do I know if a swimsuit is truly wrinkle-resistant or just marketed that way?
Check the fabric composition for high-quality synthetics (nylon or polyester) with 18-22% elastane. Feel the fabric—quality wrinkle-resistant material has a smooth, slightly dense hand feel and springs back immediately when stretched. Read reviews specifically mentioning packability and post-travel appearance.
7. Do wrinkle-resistant properties work equally well for all swimwear styles?
Performance varies by construction. Simple bikini styles and streamlined one-pieces show the best results. Structured underwire tops, ruffled details, or suits with heavy hardware benefit less from fabric technology alone and require careful packing to maintain their shape.
8. Is black swimwear more prone to showing wrinkles than lighter colors?
Ironically, yes. Dark colors create stronger shadows that highlight texture variations and creases. Medium tones like navy, burgundy, or forest green offer the best compromise between flattering appearance and wrinkle camouflage. Patterns and textures are even more forgiving.
9. Can I use fabric softener to make my swimwear feel softer without affecting wrinkle resistance?
Absolutely not. Fabric softeners coat fibers with a waxy film that reduces moisture-wicking ability and breaks down elastane over time. This actually increases wrinkling by making the fabric less resilient. Stick to gentle, residue-free detergents.
10. How many swimsuits should I pack for a week-long vacation?
Two to three quality wrinkle-resistant suits are ideal for a week. This allows each suit to fully dry between wears and gives you style options without overpacking. The quick-dry and wrinkle-resistant properties mean you can rinse and wear the same suit multiple times, unlike traditional swimwear that might need a full day to dry and lose its shape.