Duplex paper and laminated paper: understand the composition to make the right choice
Duplex is the foundation of most folding boxes in Vietnam. Knowing the difference between grey back and white back will help avoid costly rework.
Duplex paper is multi-layer board, with a white coated top for printing, and a grey or white back depending on the type, used for folding boxes for food, pharmaceuticals, and cosmetics. Laminated paper is thick board made from multiple layers, creating rigid boxes that do not fold on their own, often used for gifts and premium packaging. These two types are suitable for you if you need boxes that maintain their shape well, at a reasonable price for medium to large production.
- food folding box
- medicine and pharmaceutical box
- hard gift box
- mid-range mass cosmetics
- needs to block moisture or retain fragrance
- need to print or expose the back using grey back
Most folding boxes in Vietnam, from cake boxes to medicine boxes to affordable cosmetic boxes, use duplex paper as the core. This material is so common that many people order boxes without knowing what they are using. Understanding the composition will prevent situations where the inside of the box is gray after printing, or the box is too thin to hold its shape.
What are duplex paper and cardboard?
Duplex paper (duplex board) is a multi-layer paperboard: the top side is coated white for printing, while the back has two main variants. Grey back uses recycled fibers in the bottom layer, is cheaper, and more common in regular folding boxes. White back looks better, can be printed on both sides, and is often used when the inside of the box needs to be displayed.
The common weight of duplex board ranges from 230 to 450 gsm depending on the paper grade and supplier. This figure is only a reference when communicating with the printer, not a hard specification, as the actual caliper (thickness measured in micrometers) also depends on each specific production batch.
Paperboard is the next step: multiple layers of cardboard are glued together to form a thick, sturdy sheet, then wrapped in printed or art paper. The result is a rigid box, which is a type of box that cannot fold itself and must be manually assembled. Premium phone boxes, wine boxes, and perfume boxes are typical examples.
When to choose, when not to
Duplex is a reasonable choice when you need a sturdy folding box that maintains its shape well, with medium to large production volumes, and the budget is not in the luxury segment. Food packaging, pharmaceutical boxes, and general to mid-range cosmetic boxes are all suitable for duplex. Laminated paper is appropriate when upgrading to high-end rigid boxes, such as corporate gifts, product launches, or premium cosmetics.
- Strengths: Sturdy, maintains stable form. Grey back significantly reduces costs for large volumes. Recycled fiber core is more environmentally friendly than virgin paper. Offset printing on white surface for sharp colors. Easy to further process: lamination, foil stamping, die-cutting.
- Limitations: Grey back cannot print on the back; the inside of the box will be gray unless lined additionally. Duplex is not a moisture barrier or scent holder; a liner is required if the product comes into contact with moisture or oil. Rigid laminated boxes require manual lamination, resulting in longer lead times and higher costs than folded boxes. Foil stamping or plastic lamination reduces recyclability.
Do not choose duplex grey back when the inside of the box is exposed and needs to look good. Do not use unlined duplex boxes to directly hold moist or oily foods. If you need a refined luxury tactile feel, art paper lamination will be more suitable. If moisture, gas barrier, or airtight sealing is needed, complex laminated films are the right direction.
Costs, time and quantity
The minimum quantity depends on the printer and the type of box. Folded boxes are generally more flexible, allowing for smaller batches than glued boxes. Rigid glued boxes usually have higher minimum quantity requirements due to setup costs and manual gluing.
Sinh Vũ designs box structures, graphic layouts, and exports files ready for you to print. Sinh Vũ does not guarantee printing prices as they depend on the printer, actual paper quantities, and finishing processes, which vary by production unit.
One point to keep in mind: folded boxes require a dieline that matches precisely with the printer's die-cutting machine. If the design file does not match, the printer will have to make adjustments, which may incur additional costs. Sinh Vũ outputs files according to the specifications provided by you to avoid this situation.
What does Sinh Vũ need from you to get started
To allow Sinh Vũ to advise on the right type of duplex and outline a suitable box structure, you need to provide:
- Number of SKUs to be designed and the dimensions of the products inside (length, width, height, weight)
- Type of product: food, pharmaceuticals, cosmetics, or gifts, as each industry has different labeling requirements according to Vietnamese regulations.
- Does the inside of the box show when opened, to determine if it has a grey back or white back?
- Projected yield per print run and total annual demand
- Design budget and timeframe needed for the final file.
- Have you already chosen a printer, or do you need Sinh Vũ to suggest where to look?
Once all the above information is gathered, Sinh Vũ will propose the box structure, suitable paper type, and specific working process. You can send your request via the contact form or message directly to get started.
Decision checklist
Topic: Duplex paper and laminated paper. Sinh Vũ guide, sinhvu.com
Select each item you find appropriate, then print or save as PDF to take with you.
If you have marked most of the signs above, this is the time to discuss in more detail. Sinh Vũ can help you review and propose a direction.
References
ChinaPaperGroup, Duplex Board Explained: Grey Back vs White Back. GreyPaperBoard, Duplex Paper Board Manufacturer. PakFactory, Clay Coated Newsback Duplex Paperboard. Practical experience from Sinh Vũ Studio.
Frequently asked questions
What is the difference between grey back and white back, and which one is cheaper?
Grey back has a gray recycled fiber backing, which is cheaper and sufficient when the inside of the box is completely concealed. White back has a white backing, looks better, can be printed on both sides, and is suitable when customers can see the inside. If the budget is a priority and the inside is not visible, grey back is a reasonable cost-saving choice.
Does a duplex box protect moist or oily food?
No, duplex board is a secondary layer, meaning it is a protective and display layer, not a food contact layer. If the product has moisture or oil, an additional liner or filter bag inside is needed. Sinh Vũ will advise on the appropriate box structure once we know the product's characteristics.
How long does it take to produce a rigid box compared to a regular folded box?
The rigid box requires a manual bonding process, so the lead time is longer than that of a regular folded box. Duplex folded boxes are usually completed significantly faster. Sinh Vũ will confirm the specific timeframe based on the printer and your actual quantity.