Quick Answer
ISI-certified plywood has the BIS quality mark. This means the plywood has been tested for important things like strength, moisture resistance, and the quality of the glue used to make it.
Since 2024, BIS rules require all plywood sold in India to have ISI certification. In simple words, plywood without ISI certification cannot legally be sold in India.
Two IS Standards
Spot a Fake
You may have seen the ISI mark on plywood and assumed it means good quality. But that is true only when the mark comes from a genuine BIS-certified manufacturer. Fake ISI marks are also found in the market.
Always check the correct IS number and the manufacturer's CML number to make sure you are getting certified plywood. Dhanvardhan Ply manufactures IS 303 and IS 710 certified plywood from Yamunanagar, with verifiable CML numbers.
ISI stands for Indian Standards Institute, now replaced by the Bureau of Indian Standards (BIS). The ISI mark on a plywood sheet means the manufacturer has applied for, been granted, and continues to hold a BIS licence confirming their product meets the relevant Indian Standard (IS) for that grade.
ISI certification is not a one-time approval. BIS regularly checks certified manufacturers to ensure their plywood, raw materials, glue, and production meet quality standards. The CML number on the plywood can be used to check whether the BIS licence is still valid..
Since 2024, BIS certification is mandatory for plywood sold in India. In simple terms, plywood without a valid ISI mark cannot legally be sold in the Indian market.
What BIS tests on every certified board: Bond strength (glue shear strength - minimum 1.0 N/mm dry for IS 303, 1.5 N/mm wet for IS 710), moisture resistance (boiling water test - 8 hours for BWR, 72 hours for BWP), dimensional tolerance (thickness within ±0.5mm), and formaldehyde emission levels.Look for the triangular ISI logo with the IS number beside it, plus the CM/L number, manufacturing month and year, thickness, and batch code. Every element on a genuine ISI stamp carries specific information:
Anatomy of a genuine ISI mark on plywood
IS 303 for MR/BWR grade · IS 710 for BWP/Marine grade · IS 4990 for Shuttering grade. This number must match the grade the dealer is claiming.CM/L-12345678. Verify this at bis.gov.in.MR or BWR must be stated. For IS 710: BWR or Marine/BWP must be stated. Both grades fall under IS 710 but require the grade to be marked separately.There are counterfeit ISI stamps in the market. A manufacturer will glue a counterfeit logo on substandard plywood to lure buyers. These fakes have become more sophisticated - some look nearly identical to genuine stamps at first glance. Here is how to separate genuine from fake systematically:
Each grade is governed by a specific IS standard. The grade determines what the board was tested for not just what it claims. Here are all five grades a buyer encounters in India:
IS 303 covers plywood for general purpose. IS 710 covers Marine plywood - made from premium quality hardwood veneers with waterproof phenol-formaldehyde resin, with excellent resistance to water, humidity, fungal growth, and termites.
| Property | IS 303 | IS 710 |
|---|---|---|
| Covers grades | MR and BWR | BWP and Marine |
| Adhesive resin | UF (MR) or PF (BWR) | Undiluted PF resin throughout |
| Boiling water test | 8 hours (BWR) | 72+ hours (BWP/Marine) |
| Wet glue shear strength | 0.7 N/mm | 1.5 N/mm |
| Core void allowance | Small voids permitted | Void-free for Marine grade |
| Termite resistance | With treatment | Inherently better |
| Cost (18mm) | 45-100 per sq ft | 90-200 per sq ft |
| Right choice for | Dry to moderate humidity indoor use | Kitchens, bathrooms, outdoor, coastal |
The most important rule:
Both BWR and Marine are marked IS 710 - but the grade (BWR or Marine/BWP) should be clearly mentioned alongside the IS number. If your board says IS 710 but does not clearly state BWP or Marine - ask the dealer to show you where the grade is marked. A board that only says IS 710 without stating the grade is under-labelled.
Marine grade IS 710 is the highest quality plywood available in India under BIS standards. IS 710 Marine plywood achieves superior 1.5 N/mm wet glue shear strength with phenol-formaldehyde glue - making it ideal for the most demanding structural and moisture applications. Among nationally available ISI certified brands, CenturyPly Sainik 710 and Greenply Marine Grade BWP are the most widely cited for consistent IS 710 performance.
Birch plywood holds this distinction globally - it is dense and strong for its weight. In the Indian market, gurjan-core BWR or BWP grade plywood offers the best strength-to-weight ratio available through ISI-certified manufacturers. For applications where weight matters - wall panelling, furniture doors, flush door faces - 9mm or 12mm BWR grade with a gurjan core gives the best strength without the weight penalty of thicker boards.
For most Indian home applications: IS 303 BWR grade in 18mm is the highest-value ISI certified plywood - strong enough for all furniture, moisture resistant enough for North Indian conditions, and significantly more cost-efficient than IS 710 where waterproofing is not required.How to identify a fake ISI mark on plywood?
Five checks: 1. Run your fingernail across the stamp - genuine marks are pressed or printed into the board and cannot be peeled. A sticker stamp is fake. 2. Fuzzy prints, smeared ink, missing CM/L numbers, or mismatched IS numbers are red flags. 3. Verify the CML number at bis.gov.in - a genuine stamp resolves to an active licence with the manufacturer's correct name. 4. Check that the IS number matches the grade being sold - IS 303 on a board sold as BWP is a fake. 5. Check every sheet in a bundle - a genuine certified manufacturer stamps every board, not only the top sheet.
What are the 5 grades of plywood in India?
The main types of plywood in India include MR (IS 303) for dry indoor furniture, BWR (IS 303) for humid areas, BWP (IS 710) for kitchens and wet areas, Marine (IS 710) for outdoor and coastal use, and FR (IS 5509) for fire-resistant applications. Shuttering plywood (IS 4990) is mainly used for concrete formwork, not furniture. .
What is IS 303 plywood?
IS 303 covers moisture-resistant plywood, including MR and BWR grades. MR is suitable for dry areas with light moisture, while BWR is better for areas with moderate humidity. For kitchens, bathrooms, or places with direct water exposure, IS 710 BWP plywood is the better choice.
What is the highest quality of plywood in India?
IS 710 Marine Grade plywood is one of the highest-quality plywood options in India. It uses strong hardwood veneers and waterproof adhesive and can withstand 72+ hours of boiling water without delamination. For most homes, IS 710 BWP is more than enough; premium marine plywood is mainly useful for outdoor, coastal, or high-moisture areas. .
Which ply is better, IS 303 or IS 710?
IS 710 offers better waterproofing and is ideal for areas exposed to moisture, such as kitchens and bathrooms. IS 303 is a more affordable option for dry or moderately humid areas like cupboards and furniture. Choose the grade based on where the plywood will be used-using IS 710 where needed can prevent swelling and damage.
What is the strongest but lightest plywood?
Birch plywood offers an excellent strength-to-weight ratio. In India, 9mm or 12mm IS 303 BWR plywood with a Gurjan core provides a strong yet lightweight option for furniture, shutters, wall panelling, and flush doors. For non-load-bearing furniture, 9mm is often enough and helps reduce weight.