The same board, four names
A buyer in one market asks for ivory board, the mill quotes GC1, the converter calls it FBB, and somewhere in the middle someone quotes duplex by mistake. None of them is wrong. They are not all talking about the same thing either.
Names that usually mean the same board
Ivory board · folding boxboard · FBB · GC1 / GC2 — virgin folding boxboard. The GC letters describe the top: GC1 is coated on a white reverse, GC2 on a cream reverse. Ask which reverse, not which name.
Woodfree · uncoated woodfree · offset paper — paper made from chemical pulp with no mechanical fibre. 'Woodfree' has nothing to do with being free of wood; it means free of groundwood. Offset describes what it is printed on, not what it is.
Cupstock · PE-coated board — base board for cups, coated one or both sides. 'Single PE' and '1-side PE' are the same thing.
Names that look interchangeable and are not
Duplex vs FBB — recovered fibre with a coated top, against virgin board throughout. Both fold and print; they behave differently wet and cost differently per tonne. See the note on choosing between them.
Grey-back vs white-back duplex — the same board with the reverse lined or not. If the inside of the carton is ever seen, this is not a detail.
Greaseproof vs glassine vs MG — greaseproof resists oil, glassine is heavily calendered and dense, MG is machine glazed on one side. They overlap in use and are made differently.
How to write an enquiry that cannot be misread
Give the construction, not only the name: virgin or recovered, coated one side or two, what the reverse is. Then grammage and caliper, with a note on which of the two is the hard constraint.
Then the use. A grade name plus 'for frozen retail cartons, printed four colour, die-cut' can be quoted correctly by anyone. A grade name alone gets quoted four ways.
Questions
Is ivory board the same as FBB?
In practice, yes — both describe virgin folding boxboard. GC1 and GC2 are the same family, distinguished by how the reverse is finished. Specify the reverse and the coating rather than relying on the name.
Does woodfree paper contain no wood?
It does. 'Woodfree' means free of mechanical (groundwood) pulp, not free of wood fibre. It is chemical pulp paper.
What is the difference between grey-back and white-back duplex?
Only the reverse. Grey-back leaves the recovered-fibre reverse unlined; white-back lines it. Choose on whether the inside of the pack is visible.