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Overlap slotted container (OSC) for awkward shapes, made in Chittagong EPZ
Some loads are long, narrow or just out of proportion, and a standard carton leaves an unsupported gap where its flaps barely meet. The OSC fixes that with outer flaps that overlap partway across the box — enough to close square and stay rigid, without the full board cost of a complete overlap. We manufacture them inside Chittagong EPZ, Bangladesh, for the country's RMG exporters.
The middle ground between RSC and FOL
The OSC sits exactly between the two cartons most people know. In an RSC the outer flaps simply touch at the centre; in a full-overlap they reach all the way across and double up. The OSC overlaps by a set, partial amount — typically a few centimetres — so the closure is reinforced and the panels stay flat, while the board bill stays closer to a standard carton than a full overlap.
That middle ground matters most when the box is long and narrow. In those proportions a plain RSC can leave a wide span at the seam that flexes and racks under load. The OSC's partial overlap bridges that span, keeping the top and bottom rigid so the carton squares up on the pallet and resists twisting in transit. We build OSC cartons in A flute and AB double-wall, creased so the overlapping flaps lie flat without a bulge along the seam.
Partial overlap
Outer flaps overlap by a set amount to brace the closure on out-of-proportion boxes.
Built for long, narrow
Keeps long footprints square where a plain RSC seam would flex and rack.
Board-efficient strength
More rigid than an RSC, lighter on board than a full overlap — a balanced choice.
For proportions that fight a plain carton
If your length is much greater than your width, ask us to size an OSC. The partial overlap is often the cleanest way to get a flat, square close without over-specifying board.
- Standard proportions and even weight? A RSC master carton is simpler.
- Heavy load needing maximum top strength? Step up to a full-overlap (FOL) carton.
- Send your dimensions and we will advise — request a quote in 24 hours.
OSC FAQs
What is an overlap slotted container (OSC)?
An OSC is a slotted carton whose outer flaps are longer than an RSC's and overlap each other by a set amount, but not fully. The overlap lets the carton close square and resist racking even when the box footprint is long, narrow or out of proportion.
How is an OSC different from an RSC and a FOL?
In an RSC the outer flaps just meet; in a FOL they overlap completely; in an OSC they overlap partially. The OSC sits between the two, adding closure stability for odd proportions without the full board cost of a FOL.
When should I choose an OSC?
Choose an OSC when the box is long and narrow, or when the length-to-width ratio would leave a plain RSC with a wide unsupported gap at the seam. The partial overlap keeps the top and bottom flat and square.
Got an awkward box size?
Send the dimensions and we will tell you whether an OSC is the most economical square-closing carton for it.