Judge a shop by its bolt ends, not its bolt count
A wall of fabric tells you nothing until you read the ends of the bolts. A good shop labels every bolt with fiber content, width, and care, and the labels agree with what your hands tell you. A shop that hides content or writes only a print name is guessing, and you will be guessing too. Then look for range across fiber and weight rather than across prints: a real apparel section has lawn, poplin, twill, a couple of linens, a rayon, a knit or two, and something with wool in it, not sixty quilting cottons in different colorways. Watch a cut happen. Staff should square the fabric to the grain before cutting, not slice straight across a crooked fold, and the cut should be honest or slightly generous. Ask whether they cut in eighths or quarters of a yard; a shop that will cut a quarter yard is a shop that expects you to sample. Ask for a swatch of anything you are unsure about, and expect either a small free snip or a paid eighth. Finally, ask a real question, something like whether a particular twill will hold a pressed crease or whether the knit has enough recovery for a fitted neckband. If the answer comes from experience rather than the bolt label, you have found the right store.
Fiber content decides how the garment behaves, so learn the six
Cotton is the workhorse and comes in more weights than beginners expect: lawn and voile for blouses, poplin and shirting for shirts, twill and canvas for pants and bags, and quilting cotton, which is stiff and opaque and better on a quilt than on a body. Linen breathes, wrinkles on contact, and softens with every wash; a linen-rayon or linen-cotton blend keeps most of the look with fewer creases. Wool is the most forgiving fiber to tailor because it responds to steam, and it ranges from featherweight challis and crepe through flannel and gabardine to heavy coating. Silk comes as charmeuse, crepe de chine, habotai, and dupioni, and the slippery ones punish a dull needle and a careless cut. Rayon, labeled viscose in much of the world and most often sold as challis, along with its lyocell and modal cousins, is a regenerated cellulose fiber with the drape of silk and a strong tendency to shrink and to grow on the bias, so treat it with respect. Polyester is stable, cheap, dries fast, and does not breathe; it is the right answer for costumes, dance wear, and activewear blends with spandex, and the wrong answer for a summer dress. Blends borrow from both parents, so a cotton-spandex poplin is mostly cotton behavior with a little stretch. When the bolt says only that it is a woven, put it back.
Width is the number that quietly changes your budget
Fabric width is why two yards of one cloth finishes a dress and two yards of another does not. Quilting cottons come 42 to 45 inches wide, and some lawns and voiles do too, though many apparel lawns are 54 or wider. Most apparel wovens and knits, and most home-dec fabric, come 54 to 60 inches. Quilt backing is sold in 108-inch widths so a queen quilt needs no seam. Pattern envelopes print separate yardage for 45-inch and 60-inch fabric, and the difference is often half a yard or more, so check the width on the bolt end before you trust the smaller number. Directional prints, plaids that need matching, and napped fabrics like corduroy and velvet all add yardage because every piece has to point the same way. Add ten to fifteen percent on top of the envelope for shrinkage and for the inevitable mistake, which for a typical garment means an extra quarter to half yard. Many independents cut in eighth-yard or quarter-yard increments and sell quilting cotton in fat quarters, which is an 18 by 22 inch piece rather than a skinny strip. Some shops price and cut by the meter, which is about ten percent longer than a yard, so read the sign. If you are between amounts, round up. Nobody has ever regretted a spare half yard, and nobody has ever found the same dye lot a year later.
Pre-wash the way you will wash the finished thing
Wash and dry the yardage exactly as you plan to wash and dry the garment, before you cut. Cotton, linen, and rayon all shrink, rayon sometimes dramatically, and a dress cut from unwashed rayon challis will come out of its first wash a size smaller and a little twisted. Serge or zigzag the cut ends first, or the dryer will turn a yard of loose weave into a fringe. Wool needs different handling. Most wool is dry-clean only, so either send it to the cleaner for a steam press or steam it yourself with an iron on the wool setting, hovering just above a damp press cloth, moving slowly across the whole length. Wools sold as washable, such as superwash flannel and many wool knits, can go in cool water on a gentle cycle, but check the bolt end first. Silk should be tested on a swatch: hand-wash a corner and see whether it changes hand or loses sheen before you commit the whole cut. Polyester barely shrinks but still deserves a wash to remove the sizing and finishing chemicals, which can keep fusible interfacing from bonding and streak under an iron. Saturated reds, indigos, and hand-dyed cottons can bleed, so wash them alone with a color catcher sheet, and if the water still runs colored after two washes, quilters reach for Retayne to set the dye or Synthrapol to carry off the excess. The one exception is precut quilting bundles, which most quilters use unwashed because the pieces would fray and distort.
What a real shop stocks beyond the bolts, and what fair prices look like
The fabric wall is half of a good store. The other half is interfacing sold by the yard in woven, knit, and non-woven weights, with a fusible woven like Pellon SF101 as the default for shirts and a lighter knit fusible for stretch fabrics; polyester and cotton thread from Gutermann, Mettler, or Aurifil in real color ranges rather than a rack of black and white; zippers by the inch; Schmetz needles in the sizes and types that match the fabric on the wall; and independent patterns from companies like Closet Core, Grainline Studio, and Helen's Closet alongside the Big Four envelopes. On price, expect quilting cotton from a good mill in the low to mid teens per yard, linen from the mid teens into the twenties, rayon challis in the low to mid teens, and wool suiting or coating anywhere from the twenties to well above fifty depending on the mill. Silk runs from the high teens or twenties for habotai to considerably more for a good charmeuse, and a lawn from a premium printer like Liberty sits well above thirty. Chains sit below all of that, and there is a reason. Big-box bolts skew toward polyester, thin quilting cottons, and licensed prints, staff are rarely required to sew, and the sticker price is set to be cut by a perpetual sale or coupon, so the real price is the sale price. The bankruptcy and store closures of the largest national fabric chain made the difference less theoretical. Independents charge what the fabric costs, cut it straight, and can tell you what to do with it.