Frequently Asked Questions

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Material Origins, Botanical Sourcing & Sustainability

  1. What is mulberry paper, and what part of the plant is it made from?

    Mulberry paper is an artisanal paper made from the bast (inner fibrous bark) of the paper mulberry tree (Broussonetia papyrifera).
    Read more about the plant here

  2. What is the difference between kozo paper, mulberry paper, and Japanese washi paper, and Korean hanji paper?

    In essence, these papers are similar, 90% of the time using the very same paper mulberry tree fiber. The production methods for most mulberry papers are also largely similar. In fact, when our papers are sold in Japan, they are labeled as Washi, while in Korea, they're called Hanji. Our Western clients know them as Mulberry Paper or Rice Paper, and here in Thailand, we call them Saa Paper.
    Read more about the terminology here

  3. How do kozo fibers compare to mitsumata and gampi fibers in strength and texture?

    Kozo fibers are longer and yield higher tensile strength than mitsumata (which is softer and smoother) and gampi (which is glossy, fine, and non-porous).

  4. Why are paper mulberry fibers significantly stronger than conventional wood-pulp fibers?

    Mulberry bast fibers are significantly longer than standard wood-pulp fibers, causing them to physically entangle during sheet formation for superior tear resistance.
    Read more about kozo fiber here

  5. Are paper mulberry trees cut down permanently, or does the plant regenerate after harvesting?

    The trees are not cut down permanently; harvesters prune outer branches while the root stock remains intact to sprout new growth.

  6. Is Kozo Studio mulberry paper 100% biodegradable and compostable?

    For most products, yes. Please ask us about the specific paper at admin@kozo.studio.

  7. Are harsh chemicals used during the pulp cooking and bleaching process?

    Our standard processing involves alkaline cooking using chemicals such as caustic soda, followed by oxygen-based bleaching using agents such as hydrogen peroxide. All chemical-containing wastewater is systematically treated to ensure it meets the required standards before being recycled or safely discharged into the environment.

  8. Is mulberry paper naturally acid-free and archival?

    Yes, the inner bark fibers are naturally lignin-free and neutral to mildly alkaline, giving the paper inherent archival permanence.

  9. How does the environmental footprint of mulberry paper compare to standard industrial paper?

    Mulberry paper uses fast-growing pruned branches rather than mature tree timber, requiring less intensive chemical processing and lower overall energy.

  10. Are your mulberry papers vegan and cruelty-free?

    Yes, our standard papers use only plant bast fibers, water, and plant-based sizing, free of animal-derived additives.

  11. How is wastewater managed and recycled in your paper mill?

    We use a multi-stage wastewater-management system. Please contact admin@kozo.studio if you need details about treatment, water reuse, or supporting records for a sourcing assessment.

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Paper Specifications, Types & Characteristics

  1. What is the difference between handmade and machine-made mulberry paper?

    Handmade paper is formed sheet-by-sheet on hand moulds with four distinct deckle edges and multidirectional fiber grain, whereas machine-made paper offers uniform gauge, continuous roll lengths, a defined grain direction, and generally has two deckle edges.

  2. What does GSM mean, and what weight ranges does Kozo Studio produce?

    GSM stands for grams per square meter; we manufacture papers from ultra-lightweight 8.5 GSM tissues up to 200 GSM heavy sheets.

  3. What are deckle edges, and do all your papers feature them?

    Deckle edges are the feathered, irregular borders of paper. Not all papers have deckle edges, as some are trimmed during production. Please check the product description to see whether a particular paper has deckle edges.

  4. What is sized versus unsized mulberry paper, and how does it affect absorbency?

    Sized paper has been treated with a starch or resin sealant to prevent liquid bleed-through, while unsized paper is more absorbent. Almost all of all papers are unsized.

  5. Does mulberry paper have a distinct "front" (smooth) and "back" (textured) side?

    Yes; the mould side has a subtle screen texture, while the dried or felt-pressed side is noticeably smoother.

  6. How transparent or translucent is mulberry paper at different weights?

    Sheets under 30 GSM are semi-transparent and filter light cleanly, while sheets over 50 GSM become largely opaque.

  7. Can mulberry paper withstand getting completely wet without disintegrating?

    Generally, yes. The interlocking bast fibers give mulberry paper exceptional wet strength, allowing it to be soaked without falling apart. However, wet strength varies with the specific sheet, weight, finish, soaking time, and handling. Test a small piece using your intended process before soaking a full sheet.

  8. What standard sheet dimensions and continuous roll lengths do you stock?

    Standard sheets measure 25" × 37" (64 × 94 cm) and 22" × 30" (56 × 78 cm). Paper pack products are available in A4 format (21 × 30 cm). Continuous machine-made rolls are available in widths ranging from 94 cm to 110 cm, with lengths of up to 200 meters. Contact admin@kozo.studio for wholesale info.

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Fine Art, Calligraphy & Printmaking

  1. Which mulberry paper GSM is best for relief printmaking (linocut and woodblock)?

    Papers between 30 and 70 GSM provide the best balance of flexibility for hand-burnishing, ink pickup, and structural stability.

  2. Is mulberry paper strong enough to handle intaglio, copperplate etching, and lithography?

    Medium-to-heavy weights (100 to 200 GSM) can handle dampening and high-pressure etching beds without tearing. Before producing an edition, test the intended sheet with your dampening method, inks, plate, and press settings.

  3. Can Kozo paper be used for Gyotaku (traditional fish printing)?

    Yes; its high wet strength and pliability let it mold over fish scales and pick up fine ink impressions cleanly. The Thin Natural Kozo Paper (45 gsm, 64x94 cm) and Thin White Kozo Paper (45 gsm, 64x94 cm) are the most commonly used papers for traditional gyotaku. You can also visit this resource for more info.
    Perfect Mulberry Papers for Gyotaku

  4. Which thin paper works best for Chine-collé?

    Thin mulberry sheets between 25 and 30 GSM adhere smoothly to heavier base papers under press pressure without creating bulky ridges. Please see the GSM specification on the product page.

  5. Can I use watercolor, gouache, or liquid acrylics on unsized kozo paper?

    Yes, but unsized paper diffuses the pigment immediately; for controlled brushwork, use sized sheets.

  6. Which side of the mulberry sheet should I print or paint on?

    Artists typically paint or print on the smoother top side for detail, though the textured screen side can be used for rougher effects.

  7. Can mulberry paper be lightly dampened or conditioned before running through an etching press?

    Yes; light misting or blotting relaxes the fibers, improving plate contact and ink transfer on an etching press.

  8. Can I use dry media like graphite, charcoal, and soft pastels on textured mulberry paper?

    The natural surface tooth generally readily grips graphite, charcoal, and soft pastels. 

  9. Is mulberry paper suitable for cyanotype and traditional sun-printing processes?

    Yes; kozo's high wet tensile strength holds up through the extended water rinsing required in cyanotype printing.

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Conservation, Bookbinding & Restoration

  1. What makes mulberry paper the standard for museum and archival restoration?

    Its pure alpha-cellulose structure, lack of acid or lignin, high tensile strength, and long-term chemical reversibility make it ideal for document preservation. Visit Conservation Collection here

  2. Which ultra-lightweight kozo paper is recommended for tear mending and document lining?

    Extra-thin 8.5 are standard because they disappear visually over document repairs while stabilizing paper tears.

  3. Will archival kozo paper yellow, become brittle, or degrade over time?

    No; free of acidic wood pulp and lignin, archival kozo paper does not embrittle or discolor under museum conditions.

  4. Which adhesives are recommended for archival paper conservation (wheat starch paste vs. methylcellulose)?

    Purified wheat starch paste and methylcellulose are standard because they are archival, chemically neutral, and reversible with water.

  5. Can mulberry paper be used for bookbinding endpapers and spine lining?

    Yes; its high fold endurance makes it suited for endpapers, hinge reinforcements, and spine linings.

  6. How does heavy-weight perform as a flexible book cover material?

    Heavyweight paper offer high rub resistance and flex. However, you can also use our thinner options to wrap the hard cover.

  7. Can kozo paper be folded repeatedly without splitting or cracking along the crease?

    Yes; long bast fibers bend instead of breaking along fold lines, yielding superior fold endurance compared to wood-pulp papers.

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Crafts, Origami & Decorative Arts

  1. Can mulberry paper be used for complex origami models?

    Yes; its flexibility and tear resistance allow it to withstand repeated mountain and valley creases without tearing. See origami examples here

  2. Can kozo paper be treated with methylcellulose (MC) to make double-tissue or crisp origami sheets?

    Yes; treating thin kozo with methylcellulose (MC) produces crisp paper that holds tight, complex 3D folds. See origami examples here

  3. Why is mulberry paper preferred over wood-pulp paper for decoupage and upcycling?

    The long fibers feather into virtually invisible borders when torn, adhering smoothly around curved 3D objects without hard ridges.

  4. How do I tear mulberry paper to create seamless, invisible fiber edges in collage and decoupage?

    Brush a line of clean water along your tear line, wait a few seconds for the liquid to soften the fiber, and pull the paper apart to reveal feathered fiber edges.

  5. Can mulberry paper be used for Joomchi (traditional paper-felting)?

    Yes; kozo is the traditional fiber for Joomchi, as water agitation and manual friction felt the interlocking fibers into durable, fabric-like sheets. See more detail here: Joomchi Art Guide: How to Craft with Hanji Mulberry Paper

  6. Is mulberry paper suitable for making realistic paper flowers and petals?

    Generally, yes; it holds curl, accepts liquid dyes cleanly, and stretches gently to mimic real flower petals. Papers with a weigth of 25-70 GSM  are recommended.

  7. Can mulberry paper be machine-stitched, embroidered, or sewn into mixed-media fabric art?

    Yes; kozo will not perforate or split along stitching lines when sewn with a sewing machine or hand needle. See example here: Ephemeral Elegance with Mulberry Paper: Stephanie Reynolds and the Art of Paper Couture

  8. Can kozo paper scrap packs be mixed for scrapbooking and journal making?

    Yes; mixed scrap packs provide contrasting textures, colors, and bark inclusions that paste flat into junk journals and collages.

  9. Can mulberry paper be sculpted with papier-mâché paste into lightweight 3D vessels?

    Yes; layered over armature with wheat paste or PVA, it dries into a rigid, featherweight, semi-translucent sculpture. Generally, 25-50 GSM papers are recommended.

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Interior Design, Lighting & Architecture

  1. Is mulberry paper heat-resistant enough to use for lampshades and lantern diffusers?

    In most cases, Kozo paper can withstand normal fixture temperatures and softly diffuses light when placed at an appropriate distance from light bulbs. However, our papers are not treated with fire retardants. For this specific application, we recommend that clients treat the paper with a suitable fire-retardant chemical before use. We also recommend using LED bulbs for added safety. Read more: Choosing the Perfect Mulberry Paper for Lampshades: An Ultimate Guide

  2. Can mulberry paper be treated with flame retardant for commercial interior spaces?

    Yes; sheets can be treated with standard commercial water-based fire-retardant sprays or custom-treated during manufacturing.
    Read more: Fire Retardant and Mulberry Papers: A Quick Guide for Art & Craft

  3. Is mulberry paper suitable for Japanese shoji screens, sliding doors, and window partitions?

    Yes; traditional and reinforced kozo provides the correct tension, light diffusion, and breathability for wooden shoji screen panels. Kozo paper has been the paper for this application for thousands of year.

  4. How does sunlight and UV exposure affect the longevity and color of mulberry paper?

    Intense direct sunlight will gradually warm its tone over years.

  5. Can your papers be mounted as luxury wallpaper or acoustic wall coverings?

    Yes. However, clients may want to use a protective spray to help strengthen the paper.

  6. How do I clean or dust mulberry paper used in home decor installations?

    Dust gently using a feather duster, dry microfiber cloth, or a vacuum on low suction using a soft brush attachment.

  7. What glue or adhesive should I use to mount kozo paper to acrylic backing, wood frames, or metal ribs?

    Neutral PVA glue, methylcellulose, or clear double-sided archival mounting film work well depending on the frame substrate. Read more here: The Best Glues to Work with Mulberry Paper

  8. Can mulberry paper be cast in clear epoxy resin or polyurethane without turning cloudy?

    Yes. Low-viscosity casting resins saturate the fibers, causing the base sheet to become slightly more transparent while suspending the decorative fibers in place. Please note that metallic paper may lose its shine when cast in resin.

  9. Does heat from LED bulbs versus incandescent bulbs affect the paper differently?

    LED bulbs emit minimal heat and zero UV radiation, extending the paper's lifespan compared to hot incandescent bulbs.

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Luxury Packaging, Branding & Commercial Printing

  1. Can mulberry paper be run through commercial inkjet or laser printers?

    Yes; smooth, machine-made and sized sheets feed reliably through professional wide-format inkjet and select laser printers.

  2. Why do thin or fibrous sheets jam in desktop printers, and how can that be avoided?

    Rough deckle edges and loose fibers can snag feed rollers; using smooth machine-cut sheets or mounting thin paper to carrier sheets prevents jams.

  3. Can your paper be hot-foil stamped, blind embossed, or debossed for brand packaging?

    Yes; the tough fiber core withstands heat and compression without cracking during foil stamping or blind debossing.

  4. Is mulberry paper durable enough for rigid luxury gift box wrapping and cosmetic packaging?

    Yes; its high surface scuff resistance and flexibility prevent box corner splits during folding and wrapping.

  5. Can mulberry paper sheets be precision die-cut or laser-cut without scorching the edges?

    It die-cuts cleanly. We have not tried it using the laser cutting tool yet.

  6. Can Kozo Studio screen-print custom logos, motifs, or patterns onto sheets?

    The paper can be screen-printed. However, we are currently not offering custom printing services.

  7. Is mulberry paper certified food-safe for dry food, tea, or confectionery wrapping?

    Untreated, pure mulberry paper is non-toxic and chemically clean. However, we have not yet conducted third-party testing on all of our paper products to certify them as food-safe. Third-party testing can be arranged for specific wholesale customers upon request.

  8. Can water-resistant mulberry paper be used for floral wrapping and fresh bouquets?

    Yes; our water-resistant grades retain their strength when wrapping damp floral stems and bouquets.

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Handling, Gluing & Everyday Care

  1. What is the wet-brush feathering technique for separating mulberry sheets with natural edges?

    Apply water along the intended separation line with a wet brush, allow it to absorb for ten seconds, and pull the sheet apart by hand to preserve the feathered fibers.

  2. Which glues work best with mulberry paper without creating puckers, wrinkles, or stains?

    Neutral PVA glue, methylcellulose, or clear double-sided archival mounting film work well depending on the frame substrate. Read more here: The Best Glues to Work with Mulberry Paper

  3. How do I prevent thin kozo paper from warping when applying water-based adhesives?

    Apply the adhesive thinly and evenly to the rigid backing board rather than directly onto the thin paper sheet.

  4. How should mulberry paper sheets and rolls be stored to prevent curling, dust, and yellowing?

    Store sheets flat in acid-free folders, or rolled loosely inside wide archival tubes in a dry, temperature-controlled environment away from direct light.

  5. Can I iron mulberry paper to flatten creases, and what temperature setting should I use?

    Yes; press with a dry iron on low heat under a cotton pressing cloth or silicone release paper. You can also spray clean water to help relax the fiber before ironing.

  6. How do I flatten curled or rolled kozo paper sheets safely?

    Place the curled sheets between blotting boards under flat, evenly distributed weight for 24 hours.

  7. Can mulberry paper be tinted, dipped, or dyed at home with natural plant dyes or indigo?

    Yes; unsized kozo accepts fiber-reactive dyes, natural plant tannins, tea stains, and indigo baths. Chemical dyes also work well with the paper.

  8. How do I cut fibrous kozo sheets cleanly with a rotary blade or craft knife without pulling fibers?

    Use an ultra-sharp craft knife or rotary cutter against a metal ruler, cutting in one firm, continuous stroke to avoid dragging fibers.

  9. What should I do if my paper is stored in a humid environment to prevent mold?

    Store paper inside sealed polyethylene bags with silica gel packs.

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Wholesale, B2B Accounts & Sampling

  1. Tell me about Kozo Studio's wholesale program.

    Please visit: Wholesale & Bulk Orders

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Global Export, Logistics & Customs

  1. Which countries does Kozo Studio ship and export to?

    We export globally to more than 60 countries across North America, Europe, Asia, Australasia, and the Middle East. If you can't checkout, please reach out to "admin@kozo.studio" to inquire whether you country is eligible for delivery service.

  2. How are sheets packed to ensure corners and edges do not bend or crush in transit?

    We carefully roll the paper into a secure tube to prevent wrinkles and ensure it arrives in perfect condition.

  3. What international carriers do you use for express parcel shipping versus ocean freight?

    We ship standard orders from Thailand through Thailand Post, with your national postal service handling final delivery, such as USPS in the United States or Royal Mail in the United Kingdom. Express orders are handled by FedEx. Read more here: Shipping Guide

  4. What is the Harmonized System (HS) code used for exporting mulberry paper products?

    The standard Harmonized System codes are HS 4802.10

  5. Who is responsible for paying import duties, local VAT, and customs clearance charges?

    Our Shipping Guide explains the arrangements by destination: for United States orders, duties are collected at checkout and remitted on your behalf; for European Union orders, VAT is collected at checkout and remitted on your behalf. For other countries, VAT and duties are not collected at checkout, and any applicable import VAT or duties are payable by the recipient to the postal service or FedEx.

  6. Can I track my shipment online once it departs your facility?

    Yes. Once your order ships, we send an automated email containing your tracking number and a link to check its status. Please allow 24 hours for tracking information to become available. Check your shipment’s progress 10–15 days after ordering, as it may be awaiting customs payment, redelivery, or collection from your local post office. 

  7. Are international freight and parcel shipments insured against transit loss or water damage?

    We provide a full-refund process for damaged items: send photo or video evidence and your order number to admin@kozo.studio for verification; no return is needed. If your shipment has not arrived within 30 days, contact us so we can review it. Please ask us to confirm insurance arrangements for any freight shipment before ordering.

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Orders, Payments & Policies

  1. What payment methods and currencies do you accept for retail and wholesale transactions?

    Our online store currently accepts payment in US dollars (USD). For retail purchases, use the payment options displayed at checkout, including Visa, MasterCard, and PayPal. For wholesale orders, we accept credit card or bank transfer, as described on our Wholesale & Bulk Orders page. Please confirm the currency and payment instructions on your wholesale quotation before making payment.

  2. What is your return and refund policy for stock sheets, rolls, and scrap packs?

    You can request a return within 14 days of receiving your order. Items must be in the same condition as received, in their original packaging, with a receipt or proof of purchase. Request a return through your Orders at your customer account or email admin@kozo.studio before sending anything back; unrequested returns are not accepted. Sale items and gift cards are excluded. Approved refunds are issued to the original payment method within 14 days, with additional bank-processing time possible. See our Refund Policy for the full conditions, including the separate EU withdrawal terms.

  3. What should I do if a shipment arrives with water or handling damage from the courier?

    Inspect your order on arrival and contact admin@kozo.studio immediately with your order number and photo or video evidence of the damage. Under our Shipping Guide, damaged items qualify for a full refund after verification, and no return is needed. See our Shipping Guide for the claim details.

  4. How much natural batch-to-batch variation in shade and fiber density is normal for handmade paper?

    For a batch-specific assessment of shade or fiber density, please contact admin@kozo.studio with the product name and, if relevant, photos or a reference from your previous order. If close matching is important to your project, ask us to confirm the current batch before ordering. Product photographs are a guide, and your monitor’s colour display may not accurately reproduce the paper.

  5. Can I modify or add items to an existing order after payment has been completed?

    Please email admin@kozo.studio as soon as possible with your order number and the items or changes you would like to request. Wait for our confirmation before assuming the order has been changed; this FAQ does not guarantee that an amendment can be made. Retail orders are typically processed and shipped within 1–2 business days, excluding Sundays and public holidays, so prompt contact is important.

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