Most curtains sold in Japan advertise blackout performance or machine washability. What they rarely tell you is where the fabric came from, how much recycled content is inside, or what happens when you’re done with them.
If you’re furnishing an apartment or house in Japan and want to make a more considered choice, this guide is for you. We researched 12 products available to buy in Japan — from domestic manufacturers to international brands with Japanese storefronts — using five criteria: material origin, chemical safety, recycled content, energy performance, and durability. Information is drawn from official brand and manufacturer websites where available, and supplemented by brand-level disclosures where product-level documentation wasn’t published. Where we couldn’t verify something, we say so directly.
Who This Guide Is For
This article is written for people living in Japan — expats, long-term residents, and anyone navigating Japanese retail with an eye on sustainability. Most of these products are available through Japanese online stores, and several can be ordered entirely in English or purchased at physical locations like IKEA Japan.
A few notes before you start:
- Prices are listed in Japanese yen (¥). As of May 2026, ¥10,000 is roughly $65–70 USD.
- “Order curtains” (オーダーカーテン) means made-to-measure. Most curtain specialists in Japan operate this way — you provide your window dimensions at checkout.
- Several brands (Sangetsu, Lilycolor) primarily serve contract (non-residential) clients. Purchasing as an individual is possible but requires going through a retailer or showroom.
Quick Comparison: Find What Fits Your Priority
| Your priority | Best option | Why |
|---|---|---|
| All-in-one: material + certification + energy performance | Curtain Kurenai K-wave-D-eco48 plain | Uses GRS-certified recycled PET yarn (48%), thermal insulation data (55.3%), and Green Purchasing Law compliance all confirmed on the official site |
| Thermal performance backed by published numbers | Sangetsu Eco Funk | Heat-blocking rate of 42.2% (Eco Funk D) published with JIS test methodology |
| Natural fiber, no synthetics | IKEA DYTÅG | 100% linen, IKEA chemical standards apply, ¥12,990 for two panels |
| Domestically recycled PET only | Lilycolor ethica | Made exclusively from PET bottles collected within Japan — the sourcing origin is the point |
| Recycled material + energy data combined | Curtain Kurenai K-wave-L-eco100 re·birth | 100% recycled polyester (Teijin Frontier ECOPET), insulation 29%, UV block 93% |
| Thermal performance at an accessible price | IKEA ROSENMANDEL | Marketed as heat-insulating within IKEA’s product classification, ¥5,990 for two panels |
| Entry-level sustainable option | IKEA HÄLLEBRÄCKA | Recycled polyester or sustainably sourced cotton, ¥4,990 for two panels |
How We Evaluated These Products
We applied five criteria consistently across all 12 products. The standard was simple: can it be verified on an official website?
Material origin — Is the source of raw materials explained on the brand’s official site? Is there third-party backing, such as FSC certification for wood-based fibers, organic certification for cotton, or documented sourcing standards?
Chemical safety — Does the product hold a third-party certification for harmful substance testing, such as OEKO-TEX® STANDARD 100 (an international label that tests for 350+ restricted substances including formaldehyde, azo dyes, and pesticide residues)? Or does the brand at minimum state compliance with an equivalent standard?
Recycled content and traceability — Is the recycled material percentage disclosed? Is it backed by a certification like GRS (Global Recycled Standard — an international standard that verifies not just recycled content, but also supply chain social and environmental compliance) or Japan’s Eco Mark (エコマーク, the Japanese equivalent of the EU Ecolabel, administered by the Japan Environment Association)?
Energy performance — Are heat-blocking or thermal insulation figures published, with test methodology noted? In Japan, the standard test is JIS L 1951. Numbers without a stated test method are harder to verify.
Durability and longevity — Is there published information about wash durability, light fastness ratings, or repair/parts availability? Longer product life reduces replacement frequency and waste.
Products that couldn’t be verified on one or more criteria are noted as such. Absence of information here doesn’t mean a brand isn’t doing the work — it means we couldn’t confirm it from publicly available sources at the time of writing.
All information verified in May 2026 from primary sources (official brand and manufacturer websites).
12 Sustainable Curtains Available in Japan
1. Curtain Kurenai — K-wave-D-eco48 plain
♻️ Uses GRS-certified recycled PET yarn (48%) 🌿 Japan Green Purchasing Law compliant 🌡️ Thermal insulation 55.3% / Heat retention 29.6% 🔥 Flame-retardant label available 🧺 Machine washable / Shape-retention finish
Curtain Kurenai is the direct-to-consumer brand of Kurenai Co., Ltd., founded in 1965. Curtains are sewn domestically — at their own facility or partner factories — and sold without retail markup.
The recycled PET yarn used in this fabric is produced by crushing, washing, and melting recovered plastic bottles. Recycled content sits at 48%. The yarn is GRS (Global Recycled Standard) certified — GRS verifies not only the recycled content percentage but also that manufacturing facilities meet social and environmental standards and comply with chemical regulations across the supply chain. Whether the final curtain product itself carries a GRS product certificate should be confirmed on the official site.
Published performance figures: thermal insulation 55.3%, heat retention and cooling retention 29.6% (as stated on the official product page; test conditions should be confirmed before use for comparison purposes). On chemical safety, the brand states alignment with OEKO-TEX® STANDARD 100 principles, but a certification number has not been found on their site. “Alignment” and “certification” are different claims — worth noting before purchase.
Available in 18 colors and 140 size variations, with custom sizing also supported. Many products in the K-wave series are available with Japan’s flame-retardant label — check the individual product listing.
Editor’s note: Among the 12 products in this article, K-wave-D-eco48 plain is one of the few where GRS-certified materials, thermal performance data, and Green Purchasing Law compliance are all publicly confirmed together. If you’re cross-referencing criteria before deciding, this is a practical starting point.
Trade-offs: The 48% recycled content means the remaining 52% is virgin material. OEKO-TEX® certification number not confirmed at time of writing. Made-to-order only — not available for same-day pickup.
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2. Sangetsu — Eco Funk Series
♻️ Eco Mark certified: 50%+ recycled PET fiber 🌡️ Heat-blocking rate 42.2% (Eco Funk D) / Heat retention 32.3% 🏫 Contract-grade: suitable for schools, hospitals, public facilities 🔄 Initiative to recycle unused materials into new products
Sangetsu is one of Japan’s largest interior materials companies, founded in 1953. The Eco Funk series is built for contract environments — think schools, medical facilities, and government buildings — but the fabric is accessible to individual buyers through Sangetsu’s showrooms and retail partners.
Eco Mark certification (administered by the Japan Environment Association, the domestic equivalent of the EU Ecolabel) confirms that recycled PET fiber makes up at least 50% of the fabric composition. Certification is issued per product, not self-declared.
The heat-blocking figures are among the most detailed we found during this research: 42.2% for Eco Funk D and 38.4% for Eco Funk L, with heat retention ranging from 26.3% to 32.3%. Test methodology is JIS L 1951, and Sangetsu’s official site explains the testing procedure alongside the figures.
Separately, Sangetsu documents an initiative on their sustainability page (as of 2026) to recycle discontinued unused fabric into new products — shredding and respinning fabric rolls into recycled yarn. The scope and scale of this program should be confirmed directly with Sangetsu.
Editor’s note: For thermal performance data, Sangetsu sets a higher bar than most brands in this list. If you need to compare heat-blocking numbers across products before committing, the Eco Funk series gives you something concrete to work with.
Trade-offs: No direct-to-consumer online store. Individual buyers need to go through a Sangetsu showroom or approved retailer. This can feel slow compared to ordering online, but showroom staff are typically knowledgeable about the products.
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3. IKEA — SANELA
🌱 100% cotton, BCI-sourced 🔒 IKEA IWAY chemical standards ♻️ Circular design principles 💰 ¥7,990 for two panels
SANELA is a heavyweight velvet-style drape available at all IKEA Japan locations and online. For expats in Japan, IKEA is often the most navigable starting point — English product pages, clear sizing, and familiar checkout flow.
The cotton is sourced through IKEA’s participation in the Better Cotton Initiative (BCI), a global program that works with farmers to reduce pesticide and water use in cotton agriculture. IKEA states this sourcing policy on their sustainability pages, though individual product pages should be checked to confirm it applies to this specific item.
Chemical management is handled under IKEA’s IWAY supplier standard. OEKO-TEX® STANDARD 100 certification status should be verified on the product page directly.
IKEA’s circular design commitment covers care guidance, repair support, and take-back programs — documented across their sustainability pages.
Editor’s note: For expats who find Japanese manufacturer websites difficult to navigate, IKEA offers the most straightforward buying experience on this list. The sustainability information is published in English at the global level, even if the Japan-specific product pages are in Japanese.
Trade-offs: No published thermal insulation or heat-blocking numbers. OEKO-TEX® certification requires individual product page verification.
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4. Lilycolor — ethica
♻️ Made exclusively from PET bottles collected within Japan 🌿 Japan Green Purchasing Law compliant 🏫 Contract product: schools, hospitals, welfare facilities
Lilycolor’s ethica line was developed with a specific sourcing principle: only PET bottles collected within Japan are used. Their official site states the reasoning plainly — “waste generated in Japan should be consumed responsibly within Japan.” No blending with imported recycled material.
This distinction matters for anyone thinking about closed-loop resource cycles. Most recycled polyester products don’t specify where their source material came from. Ethica does.
The product is Green Purchasing Law compliant and is widely specified for school classrooms across Japan. Both drape and lace variants are available in the 2026 Fabric Deco catalog.
Editor’s note: The “domestic PET only” commitment goes a step further than claiming recycled content. It’s a statement about where waste comes from and where it should go. If supply chain geography matters to you, this framing is worth reading on their site.
Trade-offs: Contract product — individual buyers need to contact a Lilycolor dealer or showroom. No published heat-blocking numbers. Third-party certifications such as GRS are not confirmed at time of writing.
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5. IKEA — DYTÅG
🌱 100% linen (natural plant fiber) 🔒 IKEA IWAY chemical standards ♻️ Circular design principles 💰 ¥12,990 for two panels
DYTÅG is a natural-textured linen drape — the kind that gets softer and slightly more relaxed with every wash.
Linen (woven from flax fibers) requires significantly less water to grow than cotton, and nearly the entire plant is usable. It’s also biodegradable, which matters when thinking about end-of-life. IKEA’s IWAY supplier standards govern chemical management during production. Care information and circular design support are available on the product page.
No thermal insulation figures are published for this product.
Editor’s note: If the reason you’re choosing natural fiber is to avoid synthetic inputs and agrochemicals, linen is a straightforward answer. It won’t perform like a high-tech thermal fabric — but that’s not what it’s for. Worth approaching as a material choice rather than an energy performance choice.
Trade-offs: No heat-blocking or insulation data published. Linen can shrink in the wash — check care instructions carefully before washing.
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6. Curtain Ichiba — Recycled Yarn Curtains
♻️ Recycled PET bottle yarn (100% recycled yarn on select products) 🔄 Some products mention manufacturer-led recovery or recycling compatibility 🧺 Machine washable
Curtain Ichiba is an online-only made-to-order curtain store operating without physical retail locations. The cost savings are passed to the buyer, making this one of the more affordable options for custom sizing.
Their site lists multiple products described as “made from 100% recycled yarn” or “made from yarn recycled from plastic bottles.” Some product pages include language suggesting that the manufacturer supports end-of-life recovery or recycling, though the details — whether this is a formal take-back program, a campaign, or a general compatibility statement — are limited on the site at time of writing.
Editor’s note: The recycled yarn claim is stated on product pages, but recycled content percentages, Eco Mark certification numbers, and GRS certification are not confirmed on the site at time of writing. The take-back or recovery language on select products should be verified directly with Curtain Ichiba before factoring it into your decision.
Trade-offs: Product information varies by item — check each product page individually. Third-party certification not confirmed.
Official website：https://www.curtain-ichiba.com/
7. Curtain Kurenai — K-wave-L-eco100 re·birth
♻️ 100% recycled polyester: Teijin Frontier ECOPET 🌡️ Thermal insulation 29% / UV block 93% 🔥 Flame-retardant label 🧺 Machine washable / Shape-retention finish
This is the lace curtain counterpart to K-wave-D-eco48 plain, designed to be sold as a set. The fiber is ECOPET, a recycled polyester developed by Teijin Frontier — a major Japanese textile manufacturer — made from used plastic bottles and recovered clothing. Teijin Frontier states that ECOPET contributes to CO₂ reduction compared to virgin polyester.
Recycled content is 100%. Published performance figures (as stated on the official product page): thermal insulation 29%, UV block 93%, with day-and-night privacy screening. Flame-retardant label included as standard, along with machine washability and shape-retention finishing.
Editor’s note: A lace curtain at 100% recycled content with published insulation and UV figures is not common. If you’re building a window treatment from scratch and want both panels to be sourced consistently, the K-wave-D-eco48 + K-wave-L-eco100 set is worth considering together.
Trade-offs: OEKO-TEX® certification status requires verification on the official site. GRS certification for ECOPET should be confirmed with Teijin Frontier separately.
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8. Sangetsu — Filterie
♻️ Eco Mark certified category (recycled PET fiber) 🌡️ Heat-blocking and UV-cut performance 🏠 Available for residential purchase via WARDROBE sangetsu
Filterie is part of WARDROBE sangetsu — Sangetsu’s direct-to-consumer sub-brand that sells online without requiring a showroom visit. This makes it more accessible than the Eco Funk series for individual buyers.
The product falls within an Eco Mark-certified category using recycled PET fiber. Heat-blocking function and UV protection are stated in the product description, with performance testing based on JIS L 1951. Specific heat-blocking percentage figures should be confirmed on the individual product page or catalog.
Editor’s note: The combination of Eco Mark certification and a heat-blocking function available through an accessible online store is relatively practical for individual buyers in Japan. It sits between the full transparency of the Eco Funk data and the simplicity of the IKEA range.
Trade-offs: Specific heat-blocking percentage for individual products requires checking the product detail page. Eco Mark certification number should be confirmed there as well.
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9. IKEA — ROSENMANDEL
🌡️ Marketed as heat-insulating within IKEA's product classification ✅ IKEA quality testing standards 💰 ¥5,990 for two panels
ROSENMANDEL is marketed as a heat-insulating curtain within IKEA’s product classification — products grouped for their ability to reduce heat loss in winter and lower heating loads. This is a product category designation rather than a standardized third-party certification, but it reflects an intended functional specification.
Quality testing under IKEA’s internal standards is applied, and care and maintenance information is available on the product page.
Editor’s note: At ¥5,990 for two panels, this is one of the more accessible entry points for thermal curtains on this list. If you want to test whether heavier curtains make a difference in your apartment before committing to a higher-end option, the price makes experimentation low-risk. That said, specific insulation figures aren’t published — for number-to-number comparison, Sangetsu’s Eco Funk is the more transparent option.
Trade-offs: No published thermal insulation percentage. Recycled material and environmental certification details require individual product page verification.
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10. Sangetsu — Natural Air
🌡️ Heat-blocking + mirror finish (privacy + thermal combined) 🧺 Machine washable / Shape-retention finish 🏠 Residential made-to-order via WARDROBE sangetsu
Natural Air is a WARDROBE sangetsu residential curtain that combines heat-blocking fabric with a mirror-finish weave. The mirror effect blocks outside views during the day without darkening the room significantly — a practical solution for ground-floor apartments or street-facing windows that are common in Japanese urban housing.
Machine washability and shape-retention finishing are standard. Sangetsu’s JIS L 1951-based testing methodology applies.
Editor’s note: The thermal + privacy combination in one curtain addresses a real problem for many apartments in Japan, where windows face close neighbors or busy streets. For recycled material and certification details, check the individual product page — neither was confirmed on the general site at time of writing.
Trade-offs: Specific heat-blocking percentage requires checking the product detail page. Recycled material and certification information not confirmed at time of writing.
Official website： https://wardrobe-sangetsu.jp/collections/type-curtain-shanetsu
11. IKEA — HÄLLEBRÄCKA
♻️ Recycled polyester or sustainably sourced cotton ♻️ Circular design principles 💰 ¥4,990 for two panels
At ¥4,990 for two panels, HÄLLEBRÄCKA is the lowest-priced option in this article. The fabric uses either recycled polyester or cotton sourced under IKEA’s sustainable procurement standards — which applies varies by specific product, so check the product page before buying.
Circular design support — care guidance, repair assistance — applies as with other IKEA curtains.
Editor’s note: A reasonable starting point if you want to make a more considered fabric choice without a significant upfront cost. The low price also makes it practical for rooms where you’re not sure what you want yet.
Trade-offs: Material details (which fiber, recycled content percentage, certification) vary and require individual product page verification. No thermal insulation data published.
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12. Lilycolor — LIETA Sustainable Line
♻️ Includes Eco Mark-certified products with recycled yarn 🌡️ Thermal and insulation performance ranked by level in web catalog 🏠 Residential made-to-order
LIETA is Lilycolor’s residential curtain catalog, and the sustainable line within it includes products that carry Eco Mark certification alongside recycled yarn options. This is the residential-accessible counterpart to ethica — same material philosophy, but available through home interior dealers and showrooms rather than contract channels.
Thermal and insulation performance is presented in ranked tiers in the web catalog, with figures available per product. Showroom sample viewing is available.
Editor’s note: If you want an Eco Mark-certified curtain for your home and can visit a Lilycolor showroom or dealer, this line offers more choice than the contract-only ethica range. The ranking-based presentation of thermal performance in the catalog also helps narrow down options before committing.
Trade-offs: Eco Mark certification numbers and recycled content percentages should be confirmed per product in the catalog or through a dealer. Made-to-order, so lead time applies.
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Certification Glossary: What the Labels Mean
If you’re new to sustainable textiles, these are the certifications that appear most frequently in this article.
GRS — Global Recycled Standard verifies that a product contains recycled material and that the recycled content percentage is accurate. It also audits the entire supply chain for social, environmental, and chemical compliance. Issued by Textile Exchange.
OEKO-TEX® STANDARD 100 tests finished textile products for 350+ restricted substances — including formaldehyde, heavy metals, pesticide residues, and certain dyes. Products are assigned a class (I–IV) based on intended use; curtains typically fall in Class IV (decorative materials). The certification is issued per product and renewed annually.
Eco Mark (エコマーク) is Japan’s national eco-label, administered by the Japan Environment Association. For curtains and textiles, the criteria include minimum recycled content thresholds (typically 50%+ recycled fiber for the label; 20%+ for eligibility). It is the domestic equivalent of the EU Ecolabel.
Green Purchasing Law (グリーン購入法) is Japanese legislation that requires national and local government entities to prioritize environmentally preferable products in procurement. Products meeting the criteria are used in public schools, hospitals, and government facilities across Japan.
BCI — Better Cotton Initiative is a global nonprofit that trains farmers in more sustainable cotton agriculture, including reduced pesticide and water use. IKEA is a member. BCI is a supply chain standard, not a product-level certification.
Buying Curtains in Japan: A Practical Note for Expats
Most Japanese curtain sites are in Japanese only, but the ordering process is fairly consistent across stores:
- Measure your window width and the drop (height from the curtain rail to where you want the curtain to end).
- Enter dimensions at checkout — most made-to-order (オーダーカーテン) sites guide you through this.
- Allow 1–3 weeks for delivery, longer for specialty orders.
If you live in a standard Japanese apartment, you likely have curtain rails already installed. Japanese curtains use hook-style attachments that fit standard rails — no drilling required.
For in-person shopping in Japan, Sangetsu and Lilycolor both have showrooms in major cities. IKEA Japan has stores in Tokyo (Shinonome, Harajuku), Osaka, Nagoya, Fukuoka, and other locations.
FAQ
What does “sustainable curtain” mean in practice? In this article, it means a curtain where at least one of the following can be confirmed from an official source: the raw materials are traceable and responsibly sourced; the product has passed third-party chemical safety testing; recycled content is specified and verified; published thermal performance data exists; or the product is designed and supported for long-term use. No single curtain on this list satisfies all five — the trade-offs are part of the picture.
Are there sustainable curtains available in Japan in English? IKEA Japan is the most straightforward option for English-speaking buyers — their products are available through an English-language interface and can be shipped or picked up at stores nationwide. Other brands on this list (Sangetsu, Curtain Kurenai, Lilycolor) operate primarily in Japanese, though most modern browsers translate these sites adequately.
What is GRS certification, and why does it matter for curtains? GRS (Global Recycled Standard) verifies that recycled content claims are accurate and that the supply chain handling those materials meets environmental, social, and chemical standards. For curtains made from recycled PET bottles, GRS provides independent confirmation that the recycled content percentage stated on the label reflects reality.
What is Japan’s Eco Mark, and how does it compare to international labels? The Eco Mark (エコマーク) is Japan’s national eco-label, similar in structure to the EU Ecolabel or the Nordic Swan. For textile products, it sets minimum thresholds for recycled content and restricts certain harmful substances. It’s administered by the Japan Environment Association and is recognized in Japanese public procurement (Green Purchasing Law).
Do curtains really affect energy bills in Japan? Windows are typically the largest source of heat loss and gain in Japanese apartments, many of which have single-pane glass. Heavier curtains and thermal-specific products can reduce heating and cooling loads, particularly in winter. Sangetsu publishes heat-blocking and retention percentages tested under JIS L 1951 — the most transparent data available in this category. Effect varies by window type, room size, and building insulation.
Can I buy these curtains without speaking Japanese? IKEA Japan is the simplest option for non-Japanese speakers. For other brands, auto-translation (Google Translate, browser translation) handles most product pages adequately. For made-to-order curtains, the size input fields are standard across sites and relatively easy to navigate.
Before You Replace Your Curtains
If the curtains you already have are still functional, a few things are worth trying before buying new.
If they’re just dirty. Most Japanese curtains are machine washable. Check the care tag, use a mesh laundry bag, and run a gentle cycle. Hang them back on the rail immediately to dry — this prevents shape distortion.
If a hook is broken or the tape is worn. Curtain hooks (アジャスターフック) and heading tape are sold individually at most home stores in Japan (Nitori, Cainz, Tokyu Hands). If the fabric itself is fine, replacing hardware costs a few hundred yen.
If the shape has gone limp. Washing and re-hanging in the correct position often restores the structure, especially on curtains with shape-retention finishing.
If you want better thermal performance from what you have. Thermal lining panels can be layered behind existing curtains. Curtain specialty stores in Japan can advise on this.
A curtain that still works doesn’t need to be replaced just because it’s been a few years.
A Closing Thought
Twelve products, five criteria, and the honest answer is that no single option on this list checks every box. Something with great recycled content data often has no thermal performance figures. Something with published heat-blocking numbers isn’t always available for residential purchase. Price and certification rarely align perfectly.
That gap is the current state of the market, not a reason to give up on the question.
What would it mean for a curtain to be the right choice for your window, your building, and the way you think about materials? That’s probably a more useful question than finding the one that scores highest on a checklist.
All product information is based on official brand and manufacturer websites, verified in May 2026. Availability, pricing, specifications, and certifications may change — confirm details on each brand’s current site before purchasing.
