The right side of a fabric is the face meant to show on the finished garment; the wrong side is the one that ends up inside. On a print, the right side is the brighter, sharper one; on satin, the shinier one; on twill and denim, the side where the diagonal ribs are clearer; on jersey, the side with the little V-shaped stitches; on brushed fabrics, the fluffier one. When the two sides look the same, pick one, mark the wrong side of every piece with chalk or tape, and stay consistent through the whole project.
Why does the right side of the fabric matter?
Every instruction that says "right sides together" assumes you know which side is which. Sew a seam with one piece the wrong way round and the seam allowance ends up on the outside of the garment. Cut a pair of sleeves with both pieces facing the same way instead of mirrored and you get two left sleeves, which is the most common cutting mistake there is.
The difference between the two sides can be large (a printed cotton) or almost nothing (a plain linen). The fabric does not care, but your garment will show two slightly different shades if one front panel is cut right side out and the other wrong side out, especially under daylight. Right side and wrong side is the glossary entry; this post is about how to tell them apart on real fabric.
How do you tell the right side of a printed or woven fabric?
Work through the clues in order; one is usually enough.
Print. The side where the colors are brighter and the edges of the motif are sharp is the right side. The wrong side looks faded, as the dye has soaked through. Some prints are so saturated that both sides look good; the sharper edge still wins.
Finish and shine. Satin, sateen and polished cotton have a shiny face and a dull back; the shiny face is the right side. Brushed fabrics such as flannel, moleskin and brushed cotton are fluffier on the right side. Fabrics with a surface texture (seersucker, dobby, jacquard, embroidered cotton) show the texture cleanly on the right side and have floats, loose threads or a flatter version on the wrong side.
Weave. On twill, the diagonal ribs are more pronounced on the right side. On denim, the right side shows a diagonal that runs from lower left to upper right on most denims, and the weft threads make the back look lighter. On a plain weave such as poplin, linen or lawn, the weave is identical on both sides, so you need another clue.
Selvedge. The selvedge is the finished edge along the length of the fabric. Printed selvedges with the mill's name or color dots are usually readable from the right side. Many fabrics also have a row of small holes along the selvedge from the pins of the finishing frame; the side where the holes feel raised and rough to a fingertip is usually the right side, since the pins pushed through from the back. Check this against another clue, as it is not universal.
Fold on the bolt. Cotton and linen are most often folded on the bolt with the right sides inside, to keep the face clean; wool is more often rolled with the right side out. This is a hint about how a shop handles fabric rather than a rule.
Flaws. Slubs, knots and loose threads are more often on the wrong side, because the mill inspects the face.
Which side of jersey or other knits is the right side?
Single jersey is easy once you know what to look for. Stretch the fabric gently crosswise and look closely: one side shows small Vs stacked in columns, like the front of a hand-knitted stockinette sweater; the other shows horizontal loops or bars, like the purl side. The V side is the right side. Single jersey also curls: the cut crosswise edges roll toward the right side and the lengthwise edges toward the wrong side.
Interlock and rib knits look the same on both sides, so pick one and mark it. French terry and sweatshirt fleece have loops or a brushed surface on the wrong side and a smooth knit face on the right side; a few designs are sewn with the loops out on purpose, which is your choice, not a mistake.
What if both sides of the fabric look the same?
Choose one side as the right side and mark the wrong side of every piece as you cut, before anything moves. Do not rely on telling them apart later. Some plain fabrics have a subtle difference in sheen that shows under daylight or a lamp held at an angle, so look before you decide, and if you find one, make that the right side everywhere.
Keep an unmarked piece for reference: a corner of the fabric with a safety pin on the right side, left with your pattern until the garment is finished.
How do you mark the wrong side of fabric so you do not lose track?
- Tailor's chalk or a washable marker: a small cross on the wrong side of each piece, inside the seam allowance so it will not show. Transferring pattern markings covers the tools.
- Masking tape or low-tack sticky labels: a short strip on the wrong side, with the piece's name on it if you like. Remove it before pressing, as heat sets the adhesive.
- Safety pins: one in each piece, always on the wrong side, is the simplest method for knits.
- Leave the pattern pinned: if the paper pattern stays pinned to the fabric until you need the piece, the paper side is the side you cut from, and you can keep that consistently the right side up.
Whichever method you use, mark every piece, including small ones such as facings and pocket bags, and mark pairs as soon as they are cut. A pair cut from fabric folded right sides together comes out mirrored automatically; a pair cut from a single layer has to be flipped by hand for the second piece, which is where a missing mark causes two left sleeves.
How do right and wrong sides interact with nap and one-way prints?
Fabrics with a nap (velvet, corduroy, brushed flannel) and one-way prints add a direction to the right side: not only which face shows, but which way is up. Lay all pieces with their tops pointing the same way along the length of the fabric, and keep the right side consistent at the same time. Directional prints explains how to spot them, and the guide to laying out and cutting on grain shows the layouts that make this straightforward.
If you draft a pattern with Sewly, the sewing guide says "right sides together" at the steps where it applies and explains the term the first time, and you can ask it about any step where you are unsure which side should face which.
What is the one rule to remember?
Decide which side is the right side before you cut, mark the wrong side of every piece as it comes off the fabric, and sew with right sides together unless an instruction says otherwise. Three minutes of marking saves an evening with the seam ripper.