Reverse Tuck End Cartons: Structure, Dieline and Sheet Yield

Overview

A reverse tuck end (RTE) carton is a tube-style folding carton in which the top tuck flap hinges from one main panel and the bottom tuck flap hinges from the opposite panel. That single difference from the straight tuck end carton decides how the blank nests on the press sheet, how the pack is opened and what the buyer sees on the shelf.

• Opposing closures: one tuck flap folds from the rear panel forward, the other from the front panel backward.
• Higher sheet yield: because the closures sit on opposite edges, blanks interlock across the sheet and use less board than a straight tuck layout.
• Typical applications: retail and OTC medicine cartons, cosmetics, hardware and fast-moving consumer goods where unit cost and board utilisation decide the specification.

What an RTE blank contains

An RTE blank is a glued tube: glue lap, side panel, front panel, side panel and back panel, with closure flaps on the top and bottom edges.

• Top closure: tuck panel and tuck flap hinged to the rear panel, so the tuck seam faces away from the main display face.
• Bottom closure: tuck panel and tuck flap hinged to the opposite panel, usually the front.
• Dust flaps: folded inward first, at 90 degrees, to close the gaps at the ends and keep the carton square.
• Manufacturer's joint: a glue lap of roughly 12 to 18 mm (0.5 to 0.7 in), glued on a folder-gluer.
• Lock style: friction tuck, which relies on the fit alone, or slit locks, also called airplane locks, cut across the score so the flap latches over the dust flaps.

RTE against straight tuck end

The two structures look similar on a shelf and behave differently in production.

• Flap direction: an RTE closes from opposite panels; an STE closes both flaps from the same panel, front to back.
• Sheet yield: RTE nests more tightly. Converters commonly quote 5 to 15 percent more sheet scrap for the same carton size in STE.
• Material cost: the lower scrap rate usually shows up in the board cost per carton.
• Shelf appearance: an RTE leaves one raw cut edge visible on the top or bottom face, while an STE keeps the front perimeter unbroken.
• Markets: RTE is the default for pharmaceuticals and fast-moving goods; STE is chosen where the front face has to stay clean, as in premium cosmetics and gift packs.

Board grades used

• SBS (solid bleached sulphate), 14 to 20 pt (about 250 to 350 gsm): smooth, double-coated surface for process colour and pharmaceutical panels.
• FBB (folding box board, GC1 and GC2): more stiffness and bulk at a lower basis weight.
• CCNB (clay coated news back): recycled grey core, economical, for dry consumer goods.
• Kraft board (SUS, CUK): tear resistance for hardware and small electronics.

Sizing and blank footprint

Carton size is written as length x width x depth. Length is the horizontal opening across the display panel, width is the front-to-back opening, and depth is the height between the top and bottom scores.

• Blank width = 2 x length + 2 x width + glue tab + score allowances.
• Blank height = depth + width + tuck length + score compensation.

Because the flaps sit on opposite ends, the overall envelope is more compact when blanks are nested than the same carton built in STE, which needs two tuck lengths in the height.

Pre-press and production notes

• Confirm the step-and-repeat layout with the die-maker before printing. Interlocking tucks can gain an extra column on a standard 28 x 40 in or 40 x 56 in sheet.
• Chamfer the leading corners of the tuck flap at 15 to 30 degrees, or radius them at about R3 mm, so automatic tuckers do not catch.
• Keep the glue lap and its mating area free of ink, varnish and silicone anti-scuff agents, or the joint will not bond.
• Run board grain parallel to the depth creases so the carton stacks squarely and creases cleanly.
• Check the tuck depth against the dust flap length; a tuck that is too long will bind inside the carton instead of closing.

Related specifications

• Straight tuck end cartons: the tube carton with both tucks hinged from the same panel and an unbroken front face.
• Open end sleeve packaging: closure-free tubes used to wrap trays and band units together.
• Half slotted containers: the corrugated case for the same products once they ship.