A good fabric care guide answers three questions: what does this label symbol mean, will this fabric shrink, and how do I wash it before I sew it. Get those three right and you protect both the clothes you buy and the hours you put into a handmade project. A shrunk sweater is a bad afternoon. A shrunk garment you spent six hours cutting, sewing, and pressing is a bad month.
This page covers all three jobs in order: decoding the little symbols stitched into every garment tag, understanding why and how much different fibers shrink (polyester included), and prewashing your sewing fabrics the right way before you ever put scissors to it. Bookmark it and come back whenever a care label stumps you.
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Laundry Symbols, Decoded
Five basic symbols cover every care label: a tub for washing, a triangle for bleach, a square for drying, an iron, and a circle for dry cleaning. Dots mean temperature, lines mean a gentler cycle, and an X means don’t.
A few rules apply across all five symbols, so learn these once and every label becomes readable:
- Dots = temperature. More dots mean a hotter maximum, and the number shown is always a ceiling, not a target. You can always go cooler than the label allows; you just shouldn’t go hotter.
- Lines underneath = a gentler cycle. One line means permanent press, two lines mean delicate or gentle.
- An X through any symbol = don’t. That process is off-limits for the garment, full stop.
Tub symbols (washing)
| Symbol | Means |
|---|---|
| Plain tub | Machine wash, normal cycle |
| Tub with a hand inside | Hand wash only |
| Tub with an X | Do not wash (dry clean only) |
| 1 dot | Cold water, 65-85°F (18-30°C) |
| 2 dots | Warm water, max 105°F (40°C) |
| 3 dots | Hot water, max 120°F (49°C) |
| 4 dots | Hot water, around 140°F (60°C) |
| 5 dots | Very hot / sanitize wash, around 160°F (71°C) |
| 1 line under the tub | Permanent press cycle, a gentler wash/spin for synthetics and blends |
| 2 lines under the tub | Delicate/gentle cycle, slowest agitation, for fragile fabrics |
Square symbols (drying)
| Symbol | Means |
|---|---|
| Square with a circle inside | Tumble dry |
| 1 dot in the circle | Tumble dry, low heat |
| 2 dots in the circle | Tumble dry, medium heat |
| 3 dots in the circle | Tumble dry, high heat |
| Circle with an X | Do not tumble dry |
| Square with a vertical line | Hang to dry (line dry) |
| Square with a horizontal line | Dry flat on a towel or rack |
| Square with a diagonal line in the corner | Drip dry (don’t wring, hang while wet) |
| Twisted-fabric icon with an X | Do not wring or twist while wet |
Triangle symbols (bleach)
| Symbol | Means |
|---|---|
| Plain triangle | Any bleach may be used when needed |
| Triangle with two diagonal lines | Non-chlorine (oxygen) bleach only |
| Triangle with an X | Do not bleach |
Iron symbols
| Symbol | Means |
|---|---|
| Plain iron | Iron at any temperature as needed |
| 1 dot | Low heat, about 230°F/110°C, for synthetics and silk |
| 2 dots | Medium heat, about 300°F/150°C, for wool and polyester blends |
| 3 dots | High heat, about 390°F/200°C, for cotton and linen |
| Iron with an X | Do not iron |
| Iron with an X over the steam lines | Do not use steam |
Circle symbols (dry cleaning)
| Symbol | Means |
|---|---|
| Plain circle | Dry clean, any solvent |
| Circle with letter “P” | Dry clean, petroleum-based solvent |
| Circle with letter “F” | Dry clean, any solvent except trichloroethylene |
| Circle with an X | Do not dry clean |
If you’re not sure which fiber you’re even looking at before you check the label, our fabric types guide will help you identify it first.
Does It Shrink? (And Is It the Washer or the Dryer?)
Fabric shrinks mainly through a process textile scientists call consolidation shrinkage. Fibers get stretched under tension while they’re spun into yarn and then woven or knit into fabric. Heat, moisture, and agitation loosen that manufactured tension and let the fibers relax back toward their natural, shorter length, so the fabric contracts. Wool shrinks through a second, separate mechanism called felting: heat and agitation cause the microscopic scales on each wool fiber to catch on neighboring fibers and interlock permanently. That’s why felted wool can’t be stretched back out, while a shrunk cotton tee still has the same basic fiber structure it started with.
Both can shrink clothes, but the dryer is the bigger culprit. Hot water in the washer starts loosening the fibers’ manufactured tension, and the tumbling agitation helps that along, but it’s the dryer’s sustained heat over a full cycle, combined with continuous tumbling, that finishes and locks in most of the shrinkage. A hot wash with a cool, air dry causes far less shrinkage than a cool wash finished in a hot dryer. If you want to keep something from shrinking further, protecting it from the dryer matters more than babying it in the wash.
Does polyester shrink?
Polyester normally does not shrink: it’s a heat-set plastic fiber that resists shrinking at regular wash and dry temperatures. A normal cold-or-warm wash and a low or medium dryer setting won’t meaningfully shrink it, since polyester is thermoplastic (essentially a spun plastic fiber) and holds its shape at everyday laundry heat.
It can shrink about 3 to 5 percent, but only under sustained high heat, roughly a wash above 140°F (60°C) combined with the dryer’s hottest, longest cycle. A few sources report up to 10 percent when the heat is extreme and prolonged, but 3-5 percent is the realistic ceiling for a standard hot-wash-plus-hot-dry combo. Blended fabrics shrink according to their most shrink-prone fiber: a cotton-poly blend shrinks noticeably less than 100 percent cotton because the polyester resists while the cotton relaxes, poly-spandex tends to lose stretch and elasticity under high heat rather than shrinking outright, and poly-rayon blends carry real shrink risk since rayon is one of the most shrink-prone fibers there is.
To prevent shrinkage, wash in cold water and skip the dryer. Hang or lay flat to air dry, or use the lowest tumble-dry heat setting if you need the dryer. If you’re trying to shrink a polyester piece on purpose, wash it on the hottest setting the item allows, then tumble dry on the highest heat, checking every 5 to 10 minutes. Results are modest (a few percent) and hard to control precisely, since polyester’s resistance to heat makes shrinkage inconsistent across the garment.
Shrinkage by fiber
| Fiber | Typical shrink | Notes |
|---|---|---|
| Cotton | 3-5%+ on the first hot wash/dry | Loosely woven cottons and flannel can reach 10% or more; pre-shrunk cotton shrinks under 2%; shrinkage mostly happens once, then the fabric stabilizes. |
| Linen | 4-10% if washed/dried hot | Loosely woven or lower-quality linen can shrink up to 15%; stabilizes after the first couple of washes; cool wash plus air dry minimizes it. |
| Wool | Felts dramatically with heat + agitation (irreversible) | Once the fiber scales interlock, 10-20%+ shrinkage is common and can’t be undone; superwash wool is chemically treated to resist felting and behaves more like cotton (3-5%). |
| Rayon / viscose | 5-10% on the first wash (high) | Untreated rayon can lose up to 15% of its dimensions; can keep shrinking on later washes too, so handle it as a genuinely high-risk fabric. |
| Lyocell (Tencel) | About 3% (less than rayon) | Engineered fiber structure makes it noticeably more dimensionally stable than standard rayon/viscose, though it still shrinks some. |
| Silk | Minimal dimensional shrink | Doesn’t shrink much, but water can leave permanent spots or rings and washing dulls the sheen; handle gently since silk is weaker when wet. |
| Polyester / nylon | 0-3% typical, only under extreme sustained heat | Thermoplastic fibers resist shrinking at normal temperatures; nylon can also yellow or weaken with high heat and chlorine bleach. |
| Spandex blends | Doesn’t shrink so much as loses recovery | High heat permanently damages the elastic fibers’ ability to snap back, even if the fabric’s overall dimensions look unchanged at first. |
| Denim | 3-10% | Sanforized (pre-shrunk) denim shrinks around 3%; unsanforized raw denim can shrink up to 10% on its first hot wash. |
If a fabric ends up shrinking more than you planned for and a finished garment no longer fits right, don’t toss it. A trip through mending and alterations can often bring a slightly shrunk piece back to a wearable fit.
Prewash Before You Sew
Prewashing shrinks fabric before you cut it, not after you’ve sewn hours into a garment. It also removes excess dye and the sizing and finishing chemicals manufacturers apply to keep fabric crisp on the bolt, which gives you a truer drape, more accurate color, and cleaner pressing once the piece is finished.
The golden rule: wash your yardage exactly the way you plan to wash the finished item. If you’ll machine wash and tumble dry the garment, prewash the fabric the same way. Matching methods is what actually prevents surprise shrinkage later, since a fabric that’s already been through your normal wash-and-dry routine has nothing left to give when the finished piece goes through it again.
Finish raw edges with a zigzag stitch or serger before you toss the fabric in the wash. Loosely woven fabrics like linen and cotton gauze fray heavily in the washing machine, and unfinished edges can lose significant width to fraying alone. Once you’ve prewashed a piece of yardage properly, once is enough. You don’t need to repeat the process before every project cut from the same fabric.
Here’s how to prewash by fiber:
- Quilting cotton and linen: machine wash warm, tumble dry medium. This matches how most finished garments and quilts get washed.
- Flannel: wash and dry on hot once, to fully preshrink. Flannel keeps shrinking with repeated hot washes otherwise, so get the bulk of it out up front.
- Rayon and viscose: cold water, gentle cycle, low heat or air dry. Rayon shrinks a lot and loses strength when wet, so treat it gently.
- Wool: don’t machine wash. Steam-shrink with an iron and press cloth, send it to the dry cleaner, or hand wash in cool water with no agitation and lay flat to dry.
- Silk: hand wash in cold water or dry clean, depending on the weave and dye. Test a scrap first.
- Polyester and knit blends: normal cold wash, low tumble dry. These fibers barely shrink under normal conditions.
Many quilters skip prewashing precut fabric entirely and just square it up before cutting. That’s a common, reasonable shortcut for precuts, not a mistake, since the shrinkage on small pieces is usually manageable and squaring up corrects for it anyway.
Hand-dyed fabric deserves its own note: wash it separately for the first several washes, since hand-dyed pieces tend to release more excess dye than commercial prints. If you’re working with fabric you dyed yourself, our guide to fabric dyeing covers what to expect from those first few washes in more detail.
What not to prewash: dry-clean-only fabric, fusible interfacing (prewashing can degrade the adhesive), and, as noted above, precut quilting fabric, which most quilters simply square up instead.
Fiber-by-Fiber Care Chart
Each fiber has its own wash, dry, and iron settings, and its own thing to watch out for.
| Fiber | Wash | Dry | Iron | Watch out |
|---|---|---|---|---|
| Cotton | Machine wash warm to hot | Tumble dry medium or line dry | High heat with steam | Shrinks most on the first wash; repeated hot washing fades color over time. |
| Linen | Machine wash warm on a gentle cycle, or hand wash | Tumble dry low or air dry, avoid high heat | High heat with steam while still slightly damp | Wrinkles easily by nature; can shrink up to 10% if washed and dried hot. |
| Wool | Hand wash cold or use a wool/delicate machine cycle with wool-safe detergent | Lay flat on a towel to air dry, never hang or tumble | Medium heat with a press cloth, steam held at a distance | Felts permanently with heat and agitation combined; never wring it. |
| Silk | Hand wash cold or dry clean | Air dry away from direct sunlight | Low heat, no direct steam, press on the reverse side | Water can leave permanent spots or rings; weak and easily damaged when wet. |
| Polyester | Machine wash cold to warm | Tumble dry low or air dry | Low heat with a press cloth if needed | Attracts and holds oil-based stains and odor; a hot iron can glaze or melt it. |
| Nylon | Machine wash cold on a gentle cycle | Tumble dry low or air dry | Low heat, no steam | Weakens and yellows with high heat or chlorine bleach. |
| Rayon / viscose | Hand wash cold or gentle cold machine cycle in a mesh bag | Lay flat to dry, avoid the dryer | Low to medium heat on the reverse side while slightly damp | Weak when wet, stretches out of shape easily, and shrinks significantly. |
| Lyocell / Tencel | Machine wash cold on a gentle cycle | Tumble dry low or air dry | Low to medium heat | More dimensionally stable than rayon, but still shrinks a little and wrinkles if left damp too long. |
| Spandex blends | Machine wash cold; skip fabric softener and chlorine bleach | Air dry or tumble dry low | Low heat, quick pass, avoid direct heat on stretch panels | High heat permanently kills the fiber’s elasticity and recovery, even if the garment still looks the right size. |
| Denim | Machine wash cold, inside out | Tumble dry low or air dry | High heat with steam, inside out | Unsanforized/raw denim can shrink up to 10% on its first hot wash; sanforized denim shrinks closer to 3%. |
Quick Wins: Wrinkles and Stains
Pressing and ironing aren’t the same motion. Pressing lifts and lowers the iron straight down onto one spot, which is best for seams and tailored pieces, while ironing glides the iron back and forth, which is best for smoothing large flat areas. Use pressing on structured garments so you don’t stretch or flatten the seams. For a quick de-wrinkle with no iron at all, hang the garment in the bathroom while you shower. The steam and humidity relax the fibers and loosen light wrinkles.
Stains follow their own set of rules:
- Treat stains as soon as possible. The longer a stain sits, the more it bonds with the fabric’s fibers and the harder it is to fully remove.
- Start with cold water, never hot. Heat can cook a stain into the fabric and set it permanently before you’ve even tried to treat it.
- Blot, don’t rub. Rubbing pushes the stain deeper into the weave and spreads it into the surrounding fibers.
- Air dry until the stain is fully gone. Dryer heat sets any trace that’s left behind, essentially making it permanent.
- Use an enzyme-based detergent for protein stains like blood, sweat, grass, or egg. The enzymes break the proteins down instead of just diluting them.
- Never use hot water on blood or other protein stains. Cold water only, until the stain has fully lifted out.
Storing Fabric and Finished Makes
- Wash or dry clean an item before storing it long term. Invisible stains from sweat or food residue oxidize over months and turn into visible yellow or brown spots.
- Store clothing in breathable containers, like cotton garment bags, muslin bins, or even pillowcases, instead of sealed plastic bags or bins, which trap moisture and encourage mildew.
- Fold heavy knits and sweaters rather than hanging them. Hangers stretch out the shoulders and distort the neckline over months on the hanger.
- Use cedar blocks or lavender sachets in storage areas to repel wool moths naturally, and refresh or re-sand them periodically once the scent fades.
Every pattern in our library is written with these same care realities in mind, so you’re choosing fabrics you can actually live with over the long run. If you’d like a head start on that pairing, the 155+ printable PDF sewing patterns library walks through step-by-step instructions for each project. For more on matching fabric to a pattern before you buy, see how to choose fabric.
Frequently Asked Questions
Does polyester shrink in the dryer?
Rarely under normal settings. Polyester can shrink about 3 to 5 percent if the dryer runs on its hottest, sustained-heat cycle (above roughly 140°F/60°C), but everyday tumble-dry heat won’t shrink it.
Do clothes shrink in the washer or the dryer?
Both play a role, but the dryer causes more shrinkage. Hot water in the wash starts loosening fiber tension, then the dryer’s sustained heat and tumbling lock the shrink in.
What do the laundry symbols mean?
Five base shapes cover it: a tub means washing, a triangle means bleaching, a square means drying, an iron means ironing, and a circle means dry cleaning. Dots indicate temperature, lines mean a gentler cycle, and an X means don’t do that step. This fabric care guide breaks each group down into a full table above if you need the specifics.
How much does cotton shrink?
Untreated cotton typically shrinks 3 to 5 percent on the first hot wash and dry, though loosely woven fabrics like flannel can shrink 10 percent or more. Pre-shrunk cotton shrinks under 2 percent.
Should I prewash fabric before sewing?
Yes, for most fabrics. Prewashing shrinks the fabric before you cut it, removes excess dye and sizing, and gives you an accurate drape. Just wash the yardage the same way you’ll wash the finished item.
How do you prewash linen?
Wash on a warm machine cycle and tumble dry for a garment that will be machine-washed later, or hand wash in cool water for a gentler approach. Finish the raw edges first since linen frays heavily in the wash.
How do you shrink a shirt on purpose?
Wash it in the hottest water the fabric allows, then tumble dry on the highest heat, checking every 5 to 10 minutes. Results are modest, a few percent, and hard to control precisely, especially on polyester.
What fabrics should never go in the dryer?
Wool (felts and shrinks dramatically), silk (dulls and can water-spot), and rayon/viscose (high shrink risk) are the main ones, along with anything labeled dry-clean-only or marked with a no-tumble-dry X symbol.