Window Treatment Glossary A-Z: 50 Curtain Terms Decoded

Buyers open a curtain glossary for three reasons. Each leads to a different answer.

You are mid-configurator on a Two Pages product page and something says 2x fullness and you have no idea whether that is generous or basic. Or you are reading an install guide that mentions rod extension and overhang and the guide assumes you already know. Or you are staring at a quote from a workroom and the line item memory training, add 5 to 7 days just added a week to your bedroom project.

This glossary sorts 50 terms into 6 clusters, not alphabetically only. The order follows a real purchase flow: fabric first, then header, then lining, then measurement, then style language, then service and custom order vocabulary. If you want the wider read on measuring, hanging, and installing, the full install and measurement hub covers the pillar around this lexicon.

Terminology Reference Matrix (Scan Before You Scroll)

The 20 highest-frequency terms in one grid. If your question is on this table, the deeper definition is one cluster away.

Term	Cluster	One-line definition	Two Pages equivalent
GSM	Fabric	Fabric weight in grams per square meter	Liz Linen 140 gsm
Sheer	Fabric	Fabric under 100 gsm, translucent	Patti Voile 55 gsm
Velvet	Fabric	Cut-pile fabric, heavy hand, deep drape	Birkin Velvet 380 gsm
Pinch pleat	Header	Stitched finger pleats at the top	Liz Linen default
Rod pocket	Header	Sleeve at top the rod threads through	Rod pocket option
Grommet	Header	Metal ring at top the rod threads through	Grommet option
Ripple fold	Header	Track-mounted continuous S-wave header	Ripple fold option
Fullness	Header	Ratio of flat panel width to rod width	2x default
Unlined	Lining	No inner fabric layer, most light passes	Base config
Blackout	Lining	100 percent light block, coated multi-layer	Blackout lining
Room-darkening	Lining	85 to 95 percent light block	Room-darkening lining
Thermal	Lining	Insulating brushed lining, R-value uplift	Thermal lining
Drop	Measurement	Finished vertical panel length	Drop input
Rod width	Measurement	Bracket-to-bracket rod length	Width input
Puddle	Measurement	Extra length that pools on the floor	Puddle drop preset
Stack back	Measurement	Width the panels occupy when fully open	N/A (compute)
Colorway	Style	One named color variant of a collection	38 for Liz Linen
Dye lot	Style	One production batch of dyed fabric	Order-linked
Memory training	Service	Post-production pleat-setting process	Add-on, +5 to 7 days
Made-to-order	Service	Sewn to your specs after order	Standard, 10 to 12 days

The 30 remaining terms live in the clusters below. Cluster order follows a purchase decision, not the alphabet.

Cluster 1: Fabric & Material Terms

Fabric is where 60 percent of the price decision lives. GSM and weave family carry the drape signature, and the fiber composition explains the price band before any header or lining is added.

GSM (grams per square meter)

The industry-standard measure of fabric weight per unit area. GSM predicts drape body, opacity, and shipping weight better than any other single spec. 140 gsm like Liz Linen reads mid-weight-adjacent, hangs with body, does not swim in bright light.

Fiber composition

The percentage of each fiber in the woven fabric, listed on every product page. 100 percent linen means every yarn is linen, drapes with the signature dry hand and price. 90/10 poly-linen blends like Liz Linen deliver 85 percent of the look at half the price, at the cost of some texture.

Linen (blend vs 100 percent)

Real talk on `100 percent linen` marketing: most drapery catalogued as `linen look` is a poly-linen blend, and the ratio matters. Kyla Linen at 100 percent reads like reference-grade linen with slight irregularity and higher wrinkle. Liz Linen at 90/10 reads clean, machine-washable, and prices under half.

Polyester blend

A woven fabric where polyester is the primary or a significant fiber. Polyester blends resist wrinkling, hold color longer, wash without dye migration, and shrink 0 to 2 percent versus 3 to 10 percent for natural fibers. Trade-off: less texture, less breathability, sometimes a slightly plastic hand under direct sun.

Cotton (heavyweight vs plain weave)

Cotton drapery appears in two families. Plain weave reads casual, dries fast, prints well (Broad Cotton). Heavyweight cotton at 300 to 450 gsm carries drapery body approaching linen (Isabella Cotton 340 gsm), often with sateen or twill finish for sheen and durability.

Velvet (velour vs velvet vs plush)

Cut-pile fabrics differ by pile height and density. Velvet is short dense pile with light-catch that shifts as you walk past. Velour reads softer, less directional (Veda Luster 350 gsm). Plush is longer pile, heavier hand, better for movie rooms where deep darkness matters more than tailored drape.

Sheer

Fabric under 100 gsm, translucent by design, meant to filter light and catch breeze without blocking view. Sheers rarely stand alone in bedrooms but shine as a layer under blackout or as the sole treatment in kitchens and hallways. Fullness for sheers pushes to 2.5x for full-looking gather.

Blackout composite fabric

A woven fabric where the blackout layer is bonded to the face fabric, not added as a separate lining. Reads as 100 percent light block from a single panel, no lining upgrade needed. Trade-off: stiffer drape, heavier hand, limited colorway range (Atlanta Room Divider is the reference example).

Cluster 2: Header & Construction Terms

The header sets fullness, hardware fit, drape geometry, and roughly 20 percent of the finished price. Nine common styles cover most configurators. Two Pages surfaces all nine on the Liz Linen page.

Pinch pleat

Header style where the panel top is folded and stitched into 2, 3, or 4 finger pleats spaced every 4 to 6 inches. Built-in 2x fullness, hangs on drapery hooks and rings, produces the classic tailored drapery look. Liz Linen ships triple pinch pleat as default configuration.

Rod pocket

A sleeve sewn along the top edge of the panel that the curtain rod threads through directly. Reads casual, informal, soft gather. Trade-off: hard to slide open and closed once the rod is in place, and shows the rod bump above the fabric line. Fullness usually 1.5x to 2x.

Grommet

A header style using metal rings (grommets) punched every 6 to 8 inches along the top edge. The rod threads through the grommets, producing an even modern wave-shaped fold. Slides easily. Reads contemporary. Best on mid-weight fabrics (140 to 250 gsm); heavy velvets can pull the grommets out of alignment.

Tab top and back tab

Tab top uses fabric loops sewn to the top edge that the rod threads through, casual and often paired with sheers. Back tab hides the loops on the reverse of the panel, producing a flat clean top edge with rod-through construction hidden behind. Both hover around 1.5x to 2x fullness.

Ripple fold

A track-only header that produces a continuous S-wave drape without stitched pleats. Uses snap tape and carriers on an industrial track (not a rod). Fullness 2.2x. Reads gallery-modern, hospitality-grade, and the fold reproduces itself each time you draw the panel closed. Requires the correct track hardware, not standard rods.

Hidden tab

A back-tab variant where the loops are stitched behind and the top edge is flat with no visible rings or pleats. Reads the cleanest of all header options, best on modern minimalist walls. Fullness 2x. Rod must be routed through the hidden loops from one end (bracket removal needed for install).

Soft top and hook on

Soft top ships flat with no header construction, meant to hang from clip rings the buyer supplies. Adaptable, cheap, but requires hardware decision post-delivery. Hook on ships pre-headed with buckram and hooks already installed, ready for standard drapery rings. Workroom-preferred format for pinch-pleat installs.

Fullness ratio

The multiplier between rod width and total flat panel width. A 60 inch rod at 2x fullness needs 120 inches of flat panel across all panels combined. Pinch pleat and grommet default to 2x, sheers push to 2.5x for volume, luxury drape reaches 3x, flat rod pocket stays at 1.5x.

Cluster 3: Lining & Light Control Terms

Here is the shortest definition of lining: the second layer of fabric sewn behind the face panel that decides light block, thermal behavior, and drape weight. It also moves the price by 15 to 40 percent depending on which of the six options you choose.

Unlined

The base panel configuration with no inner fabric layer sewn behind the face. Most light passes through modulated by the face fabric only. Reads airy on linen and cotton, translucent on sheers. Cheapest option, easiest to wash, and the correct choice for sunrooms, kitchens, and layered installs.

Cotton lining

A woven cotton inner layer at 100 to 140 gsm, sewn to the reverse of the face panel. Blocks around 40 percent of light, adds visible drape body, and protects the face fabric from UV fading. Reads soft, natural, and machine-washable on most collections.

Sateen lining

A satin-weave polyester or cotton lining that reads silky and slightly reflective on the reverse. Blocks 60 percent of light. Drapes flat and even, prevents wrinkle telegraphing from the face fabric, and reads premium from the outside of the window. Common workroom upgrade.

Thermal lining

A brushed or double-weave lining engineered for insulation. Blocks 70 percent of light and improves R-value by roughly 0.5 to 1.0 depending on fabric family. Best for single-pane windows, drafty apartments, and north-facing rooms where heat loss is the bigger concern than dark sleep.

Room-darkening lining

A dense woven lining, often triple-weave, that blocks 85 to 95 percent of visible light. Reads dark but not blackout: a faint outline still shows around the panel edges at 7am. Enough for living rooms, offices, and adult bedrooms where dawn is welcome but afternoon glare is not.

Blackout lining

A coated multi-layer lining rated for 100 percent light block. The reference option for nurseries, shift-worker bedrooms, and home theaters. Reads heavier, adds stiffness to the drape, and can raise total panel weight by 30 to 50 percent. Requires stronger rod brackets on wide windows.

Interlining

A third inner fabric layer sewn between face and lining, usually a soft flannel or bump cloth. Adds drape body, sound absorption, and thermal insulation without changing the visible face. Reserved for luxury installs on tall windows or historic homes where the panel must read weighted and full even at 3x fullness.

Cluster 4: Measurement & Install Terms

The vocabulary that appears on every configurator, and the vocabulary a bad quote hides behind. The Two Pages measurement guide is the brand primary source; the site’s 5-step measurement method walks the flow from tape to cart.

Drop (finished panel length)

The finished vertical length of the panel, measured from the top of the header ring or grommet to the bottom hem. The second most-used configurator input after rod width. Standard drops match four conventions: sill length, apron length, floor kiss, puddle. Two Pages accepts custom drops to the 1/2 inch.

Rod width and bracket-to-bracket

Rod width is measured bracket to bracket, not window frame to window frame. This is where 30 percent of first-time buyers underspec their panel width. The rod extends past the window on each side (rod extension), and the panel width has to cover that extended span at the chosen fullness ratio.

Sill, apron, floor kiss, puddle

Four standard drop conventions covering 95 percent of installs. Sill length ends at the windowsill (kitchens, cafes). Apron length ends below the sill trim (kitchens, mudrooms). Floor kiss ends 1/2 inch above the floor (living rooms, bedrooms, tailored default). Puddle pools 2 to 6 inches on the floor (formal rooms, romantic drape).

Wall mount vs ceiling mount

Wall mount attaches the rod to the wall above the window frame, standard install. Ceiling mount attaches the rod to the ceiling directly, adding drop length and reading taller. Ceiling mount is the correct choice for windows within 4 inches of the ceiling, and for rooms where the goal is visual height.

Rod extension and return

Rod extension is the distance the rod runs past each side of the window frame, usually 6 to 12 inches per side. Adds coverage width and lets the panel stack fully off the glass when open. Return is the elbow at each end where the rod turns 90 degrees back into the wall, usually 3 to 4 inches, blocks side light.

Overhang (curtain reveal)

The distance the rod sits above the top of the window frame, usually 4 to 12 inches. Overhang decides visual ceiling height. A high overhang (10 to 12 inches or ceiling-mounted) reads dramatic and taller; a tight overhang (2 to 4 inches) reads standard hotel-window install.

Panel count

The number of panels ordered per window. Two panels is the residential default (one per side, they part in the middle). One-panel installs suit narrow windows under 40 inches and modern one-sided sliding drape. Three and four panels are used on picture windows and sliding doors wider than 100 inches.

Center gap and stack back

Center gap is the small opening between two closed panels at the middle of the rod, usually 2 to 4 inches, minimized by rod overlap hardware or overlapping master carriers on tracks. Stack back is the width the fully open panels occupy against the wall, usually 15 to 25 percent of total rod width.

Break and puddle length

Break is a 1 inch overlap where the panel just meets the floor and rests slightly, halfway between floor kiss and puddle. Reads clean and lived-in. Puddle length is the amount of fabric pooling on the floor, from a light 2-inch touch to a full 6-inch trail depending on formality.

Cluster 5: Style & Design Terms

The vocabulary designers and homeowners use to describe drape geometry and color language. This is where the difference between colorway and dye lot becomes a real complaint on a real order form.

Colorway

A named color variant of a fabric collection. Liz Linen has 38 colorways, from Snow White through Sand Beige to Charcoal Grey. Each colorway is a stable production spec across seasons, printed on the catalog and confirmed on the swatch booklet.

Dye lot

A single production batch of dyed fabric. Same colorway, same intended color, but two different dye lots can differ by 2 to 3 percent in visible tone. Industry standard, not defect. If you order additional panels months after the original install, request the same dye lot when available.

Weave (plain, twill, sateen, jacquard)

The pattern by which warp and weft yarns cross. Plain weave is flat balanced (Liz Linen). Twill reads diagonal with more drape weight. Sateen hides warp yarns under long weft floats, producing sheen. Jacquard is programmable multi-color pattern woven into the fabric (Stefana Silber Print).

Texture and hand feel

Two words for the same thing. Texture is the visible surface irregularity: linen slub, velvet pile direction, jacquard relief. Hand feel is the tactile experience: dry vs soft, crisp vs fluid, warm vs cool. Swatches are the only reliable way to judge either before ordering.

Drape (verb and noun)

As a verb, drape means the way the fabric falls under its own weight (Liz Linen drapes with body). As a noun, drape means the finished window panel itself, often used interchangeably with curtain in the industry but implying pleated construction and lining. Drapery is the collective term.

Pattern repeat

The vertical distance between identical pattern elements on printed or woven fabric. Standard repeats run 6 to 24 inches. Pattern repeat drives yardage math: each cut rounds up to the next multiple of the repeat to keep panels aligned. Solid fabrics have zero repeat.

Motorization ready

A header and rod configuration compatible with motorized track systems (Somfy, Lutron, generic RF motors). Requires ripple fold or specialty grommet header, industrial track, and hardwired or battery-powered motor. Adds $300 to $1200 per opening. Reserve for master bedrooms and tall picture windows where cordless is a real value.

Layer system (sheer plus blackout)

A two-rod install where a sheer sits on the inner rod (closer to the window) and a blackout or heavy panel sits on the outer rod. Sheers filter day light; blackouts deliver dark sleep. The layer system doubles the vocabulary count (two headers, two linings, two rod widths) but solves rooms where light control varies by hour.

Cluster 6: Service & Custom Order Terms

The vocabulary of made-to-measure versus ready-made, and the language of the small print on custom order pages. The WCAA industry resources document the workroom side of these terms.

Made-to-order

Panels sewn to the buyer’s exact width and drop after the order is placed. Two Pages ships made-to-order in 10 to 12 days. Ready-made panels ship instantly but only at fixed sizes (typically 50-inch or 100-inch wide, 84 or 108 drop). Made-to-order eliminates alteration cost and fits the window on install day.

Ready-made

Panels sewn to standard sizes and stocked for immediate shipping. Cheaper per panel, sometimes 40 to 60 percent below made-to-order, but standard sizes never fit non-standard windows without hem alteration or pinning. Ready-made shines on rental apartments and starter homes; made-to-order wins on owned homes with permanent windows.

Memory training

Where the vocabulary gets tricky. Memory training is a specialty post-production process where the finished panel is folded, steamed, and wrapped so the pleats hold a uniform shape from day one. Adds 5 to 7 days to lead time and $20 to $40 per panel. Skip it and expect 2 to 4 weeks of manual pleat training.

Lead time (production vs shipping)

Two-part measurement. Production lead time is the number of days the workroom takes to sew the panels after order confirmation (Two Pages: 10 to 12 days standard, +5 to 7 with memory training). Shipping lead time is transit from workroom to door, usually 3 to 7 days ground. Configurator prices exclude shipping and tax until checkout.

OEKO-TEX Standard 100

A textile certification, listed on the OEKO-TEX Standard 100 registry, confirming every component of the fabric (yarn, dye, finish, thread) has been tested against over 350 substances harmful to health. Two Pages linings and most fabric collections carry this certification. Matters most for nursery, kids room, and bedding-adjacent installs.

Swatch

A small cut of the actual fabric mailed to the buyer for hand-check before ordering. The Liz Linen booklet contains all 38 colorways for $3.99. Swatch dye lots and production dye lots can differ 2 to 3 percent, so treat the swatch as directional not exact. Pin it to the wall under 5pm and 9am light before deciding.

Configurator

The online form that maps every glossary term above to a real product field: rod width, finished drop, header style, fullness ratio, lining option, memory training add-on, colorway. Reads a lot cleaner once the vocabulary is decoded. Every wrong term entry costs either a $60 alteration or a full remake.

The Two Pages Configurator, Term by Term

If it were my configurator, I would read the form in this order. First the rod width and finished drop from cluster 4 (Measurement). Then the header style and fullness ratio from cluster 2 (which decide flat panel width and hardware). Then the lining option from cluster 3 (which decides light and price). Then the colorway from cluster 5. Then the memory training add-on from cluster 6. Then checkout.

The Liz Linen configurator surfaces all of these on one page. A wrong entry on any of them costs either an alteration fee (usually $60 to $90) or a full remake at owner cost. The vocabulary above is the way to avoid both.

FAQ

What is GSM in curtains?

GSM stands for grams per square meter, the standard curtain fabric weight measurement. Under 100 gsm reads as sheer, 100 to 160 gsm as light drapery, 160 to 250 gsm as mid-weight (where Liz Linen sits at 140 gsm), 250 to 400 gsm as heavyweight, 400+ gsm as blackout composite. Higher GSM improves drape body and thermal behavior but also lifts shipping cost and makes hardware selection more critical.

What does 2x fullness mean for curtains?

Fullness ratio is the multiplier between rod width and total flat panel width. 2x fullness means a 60 inch rod carries 120 inches of flat panel across all panels combined, so the drape reads full and pleated rather than stretched flat. Pinch pleat and grommet defaults sit at 2x. Sheers push to 2.5x for volume, luxury drape reaches 3x, flat rod pocket stays at 1.5x.

What is memory training on curtains?

Memory training is a specialty post-production process where the finished panel is folded, steamed, and wrapped so pleats hold a uniform shape from day one. Two Pages offers it as an add-on. It adds 5 to 7 days to lead time and roughly $20 to $40 per panel. Owners who skip it report 2 to 4 weeks of manual pleat training after unpacking.

What is the difference between blackout and room-darkening curtains?

Blackout means 100 percent light block, achieved with a coated multi-layer lining or blackout composite fabric. Room-darkening blocks 85 to 95 percent and lets a faint outline through around the panel edges. Blackout is the only spec that reads truly dark at 7am in a south-facing bedroom. Room-darkening is enough for living rooms and offices.

What is a curtain drop?

Drop is the finished vertical panel length from the top of the header ring or grommet to the bottom hem. It is the second most-used input on any configurator after rod width. Standard drops match 4 conventions: sill length (to windowsill), apron length (below sill trim), floor kiss (1/2 inch above floor), puddle (2 to 6 inches on floor).

What is a pinch pleat?

Pinch pleat is a header style where the top of the panel is folded and stitched into 2, 3, or 4 finger pleats spaced every 4 to 6 inches. It carries built-in 2x fullness, hangs on drapery hooks and rings, and produces the classic tailored drapery look. Two Pages Liz Linen ships with a triple pinch pleat header as default configuration.

What is OEKO-TEX Standard 100?

OEKO-TEX Standard 100 is a textile certification confirming that every component of the fabric (yarn, dye, finish, thread) has been tested against a list of over 350 substances harmful to health. Two Pages linings and most fabric collections carry this certification. It matters most for nursery, kids room, and bedding-adjacent installs.

Vocabulary Down. Now Configure.

The 50 words above are what the Two Pages configurator asks for in one form: drop, width, header, fullness, lining, memory training, colorway. Every term has a real dollar and real day consequence on the finished panel. The definitions cover the vocabulary; the configurator turns them into an order.