Ribbed Smoked Sheet
Ribbed smoked sheet is natural rubber coagulated from field latex, rolled into ribbed sheets and dried in a smokehouse, which both removes water and lays down the phenolic compounds that give the sheet its colour and its resistance to mould. It is the oldest traded form of dry natural rubber and it remains the preferred feedstock where the finished article needs high green strength and clean processing: truck and aircraft tyres, conveyor belting, engine mounts, bridge bearings and heavy industrial mouldings.
Listed ribbed smoked sheet markets
Each line is a grade at a delivery point. Open one for its full specification and terms.
Grades
Ribbed smoked sheet is graded visually, not by instrument. The Green Book sets the grades and they are settled by inspection of the sheet against the standard, in daylight, by an accredited grader.
Green Book visual grades for ribbed smoked sheet
9 grades
| Grade | Definition |
|---|---|
| RSS 1XRibbed smoked sheet 1X | The highest grade. Dry, clean, strong, sound and free of blemishes, resinous matter, blisters, sand, dirty packing and any other foreign matter. No mould, no oxidation, no burn, no undersmoked sheet. |
| RSS 1Ribbed smoked sheet 1 | As RSS 1X, with slight specks of bark permitted and mould on wrappers and on the outer surface of the bale tolerated at the stated limit at the time of delivery. |
| RSS 2Ribbed smoked sheet 2 | Small bubbles and slight specks of bark permitted. Dry mould on the bale surface and on the sheets is tolerated to a stated proportion of the bale. |
| RSS 3Ribbed smoked sheet 3 | Medium sized bubbles, specks of bark and slight blemishes permitted. The standard commercial grade in world trade and the reference against which the ladder is priced. |
| RSS 4Ribbed smoked sheet 4 | Medium bubbles, bark specks, slightly sticky, slightly over-smoked and slightly under-cured sheet permitted within the stated limits. |
| RSS 5Ribbed smoked sheet 5 | The lowest listed grade. Large bubbles, bark specks and blemishes permitted to the stated limits. Below this the material is off grade and is contracted as cuttings or as scrap. |
| Air dried sheet, ADSAir dried sheet | Coagulated and rolled the same way but dried without smoke. A pale, translucent sheet, contracted separately. |
| Pale crepe and sole crepeGreen Book crepe grades | Machine crepe rubber graded on colour and cleanliness. A distinct article from sheet and never a substitute delivery. |
| Cuttings and off gradeDeclared | Sheet failing the listed grades. Named, never delivered against a listed grade. |
Instrumental tests contracted alongside the visual grade
8 grades
| Grade | Definition |
|---|---|
| Dirt contentPercentage by mass, maximum | ISO 249. Retained on a stated sieve after solvent dissolution. The single most contracted number in dry rubber. |
| Ash contentPercentage by mass, maximum | ISO 247. Residue after ignition. |
| Volatile matterPercentage by mass, maximum | ISO 248. Loss on drying, effectively the residual moisture. |
| Nitrogen contentPercentage by mass, maximum | ISO 1656. A proxy for the protein carried through from the field latex. |
| Initial plasticity, PoWallace units, minimum | ISO 2007. Rapid plastimeter reading on the unaged sample. |
| Plasticity retention index, PRIPercentage, minimum | ISO 2930. Plasticity after ageing as a percentage of initial plasticity. It measures resistance to thermal breakdown and it is what a compounder reads first. |
| Mooney viscosityMooney units, range | ISO 289. Shearing disc viscometer, run at the temperature and the rotor stated on the contract. |
| Colour indexLovibond units, maximum | ISO 4660. Contracted where the finished article is light coloured. |
Presentation and legality
4 grades
| Grade | Definition |
|---|---|
| Bale, packing and wrappingDeclared, with the bale mass, the wrap and the pallet or crate | Sixty and thirty three and a third kilogram bales, polyethylene wrapped, shrink wrapped pallets or wooden crates. It is a delivery term and it is priced. |
| Smokehouse and factory of originDeclared | Named factory, with its grading licence. Sheet is a factory article and the factory is on the contract. |
| Traceability and legality fileDeclared, to plot or to concession | Where the destination is the European Union, the deforestation regulation due diligence file travels with the lot and is part of the deliverable. |
| CertificationCertificate, with the scheme and the certificate number | Forest Stewardship Council, Rainforest Alliance, GPSNR member supply or an organic certification, named on the contract when it is contracted. |
Grades outside this list trade on request. Send us the contract specification you work to and we will price against it.
Locations
| Country | Region | We trade it as |
|---|---|---|
| Thailand | Songkhla, Surat Thani, Nakhon Si Thammarat, Yala | Origin and destination |
| Indonesia | North Sumatra, South Sumatra, Jambi, Kalimantan | Origin and destination |
| Vietnam | Binh Phuoc, Tay Ninh, Gia Lai, Dak Lak | Origin and destination |
| Malaysia | Johor, Kedah, Perak, Sabah | Origin and destination |
| India | Kerala, Tamil Nadu, Tripura, Assam | Origin and destination |
| Sri Lanka | Kegalle, Ratnapura, Kalutara, Galle | Origin and destination |
| Cambodia | Kampong Cham, Tboung Khmum, Ratanakiri | Origin and destination |
| Myanmar | Mon, Tanintharyi | Origin and destination |
| Laos | Luang Namtha, Champasak | Origin and destination |
| China | Hainan, Yunnan | Origin and destination |
| Philippines | Zamboanga, Basilan | Origin and destination |
| Papua New Guinea | Western, Central | Origin and destination |
| Ivory Coast | Southern, Aboisso, San Pedro | Origin and destination |
| Nigeria | Delta, Edo, Ogun | Origin and destination |
| Liberia | Margibi, Grand Bassa | Origin and destination |
| Ghana | Western | Origin and destination |
| Cameroon | Southwest, Littoral | Origin and destination |
| Guinea | Forest region | Origin and destination |
| Gabon | Woleu-Ntem | Origin and destination |
| Brazil | Sao Paulo, Mato Grosso, Bahia | Origin and destination |
| Guatemala | Escuintla, Izabal | Origin and destination |
| Mexico | Veracruz, Chiapas, Tabasco | Origin and destination |
| Bangladesh | Chittagong Hill Tracts | Origin and destination |
| Thailand | Rayong, Chanthaburi | Origin and destination |
| United States | Ohio, South Carolina, Akron | Destination |
| Germany | Nationwide | Destination |
| France | Nationwide | Destination |
| Italy | Nationwide | Destination |
| Spain | Nationwide | Destination |
| Poland | Nationwide | Destination |
| Turkiye | Nationwide | Destination |
| Japan | Nationwide | Destination |
| South Korea | Nationwide | Destination |
| Netherlands | Rotterdam | Destination |
| Belgium | Antwerp | Destination |
| Singapore | Nationwide | Destination |
| United Arab Emirates | Jebel Ali | Destination |
| Canada | Nationwide | Destination |
| South Africa | Nationwide | Destination |
| Egypt | Nationwide | Destination |
Origins and destinations outside this list trade on request. We are not limited to the locations shown here.
Timing
Harvest here is the tapping season, when latex is drawn from the tree. Arrival is when a shipment from that origin typically lands in a consuming market. The gap between them is coagulation, sheeting, smoking, grading, baling and the voyage.
HarvestArrival
| Origin | J | F | M | A | M | J | J | A | S | O | N | D | Window |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Thailand | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Arrival | Harvest | Harvest and arrival | Harvest and arrival | Harvest Oct to May, arrival Nov to JunTapping runs through the year and is heaviest from the late rains into the early dry season. February to April is the wintering break, when trees shed leaves and yield falls hard. Thailand is the price setting origin for sheet. | |||
| Indonesia | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest Jan to Dec, arrival Jan to DecNear continuous tapping with a monsoon dip. Most volume moves as technically specified rubber rather than sheet. |
| Vietnam | Arrival | Harvest | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest May to Dec, arrival Jun to JanTapping season opens in the second quarter and closes over the wintering break in the first. | |||
| India | Harvest and arrival | Harvest and arrival | Arrival | Harvest | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest Sep to Feb, arrival Oct to MarPeak tapping after the southwest monsoon. Most Indian sheet is consumed domestically. | |||||
| Sri Lanka | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest Jan to Dec, arrival Jan to DecYear round tapping with monsoon interruptions. Sri Lanka remains a specialist sheet and crepe origin. |
| Malaysia | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest Jan to Dec, arrival Jan to DecYear round, with a wintering dip in the first quarter. |
| Cambodia | Arrival | Harvest | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest May to Dec, arrival Jun to JanTapping through the wet season and into the early dry, shipped through Sihanoukville and through Vietnam. | |||
| Myanmar | Harvest and arrival | Arrival | Harvest | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest Jun to Jan, arrival Jul to FebWet season into dry season tapping. | |||
| Ivory Coast | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest Jan to Dec, arrival Jan to DecYear round tapping and the largest African origin, though the bulk of the crop moves as technically specified rubber. |
| Brazil | Harvest | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Arrival | Harvest Mar to Oct, arrival Apr to NovTapping concentrated in the drier months. |
Windows outside this pattern trade on request, including carry, forward positions and stock already sitting in a destination warehouse.
Customs, packing and contract terms
Indicative terms for ribbed smoked sheet. Tariff classification is the importer’s responsibility and limits change, so confirm both against the destination customs authority and the current regulation before you fix a contract.
- HS heading4001.21 Natural rubber in smoked sheets
- PackingTSR in 33.33 kg bales, shrink wrapped, on 1.2 t pallets. RSS in 111.11 kg bales. Latex concentrate in flexitanks, IBCs or 205 kg drums with the ammonia content declared.
- Container loading20ft: 20 t of TSR or RSS. Latex concentrate at 20 t to 22 t in a flexitank. Stow away from heat and direct sun.
- Contract and arbitrationInternational Rubber Association contracts, with technical specification under ISO 2000 for TSR and the Green Book visual grading for RSS. SICOM and TOCOM specifications set the deliverable grades. Arbitration under the rules of the rubber trade association at the contract seat.
- Destination limitsEUDR (Regulation 2023/1115) due diligence with plot geolocation applies to natural rubber. EU REACH restricts nitrosamines and PAHs in downstream articles. Latex concentrate carries an ammonia declaration and IMDG classification where the ammonia content requires it.
Common questions
What grades of ribbed smoked sheet does SIP Global trade?
We quote 21 published grades of ribbed smoked sheet, including RSS 1X - Ribbed smoked sheet 1X, RSS 1 - Ribbed smoked sheet 1, RSS 2 - Ribbed smoked sheet 2, RSS 3 - Ribbed smoked sheet 3, RSS 4 - Ribbed smoked sheet 4 and RSS 5 - Ribbed smoked sheet 5. Every grade is tied to a delivery point and a settlement route. Grades outside the published list are priced on request.
How is ribbed smoked sheet graded?
Ribbed smoked sheet is graded visually, not by instrument. The Green Book sets the grades and they are settled by inspection of the sheet against the standard, in daylight, by an accredited grader. Grading runs on 3 systems: Green Book visual grades for ribbed smoked sheet, Instrumental tests contracted alongside the visual grade and Presentation and legality.
Where does SIP Global trade ribbed smoked sheet?
We trade ribbed smoked sheet in Thailand, Indonesia, Vietnam, Malaysia, India, Sri Lanka, Cambodia and Myanmar and 32 further markets. Origins and destinations outside this list trade on request. We are not limited to the locations shown.
When is ribbed smoked sheet harvested and when does it arrive?
Typical windows are Thailand: harvest oct to may, arrival nov to jun; Indonesia: harvest jan to dec, arrival jan to dec; Vietnam: harvest may to dec, arrival jun to jan; India: harvest sep to feb, arrival oct to mar; Sri Lanka: harvest jan to dec, arrival jan to dec. Harvest is when the lot is taken at origin, arrival is when a shipment from that origin lands in a consuming market. Windows outside this pattern, including carry, trade on request.
What is the HS code for ribbed smoked sheet?
Ribbed smoked sheet is normally classified under HS 4001.21 (natural rubber in smoked sheets). The heading follows the form the goods are in at the border, and national tariffs extend it beyond six digits, so confirm the full line with the destination customs authority before you fix a contract.
How do I get a price for ribbed smoked sheet?
Send the grade, the origin and the delivery window to the SIP Global desk. That is enough for a trader to come back with a level and a settlement route. 1 listed ribbed smoked sheet market is published on this page, each with its full specification and terms. We take both sides, physical and financial, prompt to long dated.
Standards and data sources
The grading language on this sheet follows published standards. Trade volumes and tariff lines are public record. Verify anything here against the source.
- ISOInternational Organization for Standardization
- FSCForest Stewardship Council chain of custody
- UN ComtradeOfficial international trade statistics by HS code
- ITC Trade MapBilateral trade flows and tariff data
- FAOSTATFAO production and trade series for agricultural commodities
Price this with our desk
Grade, origin and window if you have them. If what you are carrying does not fit the sheet above, describe it in your own words and a trader will take it from there.