Order the width your converting step needs — finished part, plus trim, plus what your machine grips — as a band rather than one number, so the supplier can check how many cuts it yields from the master roll before the price is fixed. Then ask whether the remainder is charged to you.
Where slitting waste comes from
Waste is the remainder: the master roll width is fixed per construction, your width is cut from it as many times as it will go, and the strip after the last full cut usually cannot be sold on.
Usable master width is not one number. A metalliser runs a range of base-film widths, and a laminate is bounded by its narrowest component — scrim loom width on a woven laminate, foil width on a foil laminate. A width that cuts cleanly from plain VMPET may not from foil-scrim or foil-bubble, so the yield check is per construction: send width and construction together.
Whether the remainder is charged to you, absorbed or resold depends on their stock widths and other customers, so ask in writing. A quotation with no master width, cut count or remainder is a bad answer; a good one shows them or proposes an alternative width alongside yours.
A worked illustration, using example numbers only
A small width increase can cost far more than the extra material, because it can drop the number of full cuts per master roll by one.
These numbers are arbitrary; they do not describe the master roll of any construction we supply, and usable width is confirmed in writing for what you buy.
- Example master roll — 1,500 mm usable after edge trim.
- Order 375 mm — four full cuts, nothing left.
- Order 395 mm — three full cuts, 315 mm remainder.
- The difference — 20 mm added “for safety” costs roughly a quarter more per usable square metre once it pushes the fourth cut off the roll.
- Nest your own widths — 2 × 375 mm plus 1 × 750 mm also uses 1,500 mm cleanly; two products that do not fit alone may fit together, so say if you buy several widths.
Work backwards from your own converting step
Build the width outwards from the finished part — part width, plus trim, plus edge grip, plus web wander — then state the range that still works, not one number.
- Part, trim, grip, wander — the delivered dimension, the edge you cut or seal away, what clamps and nips hold, and sideways drift on thin, soft or embossed webs.
- Tolerance stack — supplier slit tolerance plus yours, added not averaged; ask whether it is symmetrical or one-sided, and if the part cannot survive a narrower web, ask for plus-only.
- Slit edge by construction — woven laminates leave cut yarn ends that can fray on a second slitting pass; a foil-bubble slit runs through bubble caps rather than between them; embossed film shows the pattern truncated at the edge; slit foil laminate edges are sharp for the handling crew. Size the trim to cover it.
- A second width you can use — consuming the remainder strip yourself turns scrap into a second usable width and changes the yield arithmetic; its price is confirmed in the quotation.
If, for example, 372 mm to 380 mm all work on your machine, say so. On arrival, measure width at several points along the roll and at both ends, not once at the outer wrap.
Roll length, diameter and weight
State which of metres per roll, outer diameter or roll weight is the binding limit on your unwind, and let the supplier back out the other two from the construction’s thickness.
All three together invite a conflict: on foil-bubble and foil-foam outer diameter binds after a short length, on thin metallised PET weight or shaft rating binds first; see mil, micron, gsm and denier.
- Diameter, weight, route — clear the unwind frame and guarding, check lifting gear and shaft rating, and the route: container door, lift, corridor, anything turned on end.
- Length basis — declared nominal or guaranteed minimum, agreed alongside the invoicing basis: per square metre, linear metre, kilogram or roll. A nominal length with a minus tolerance invoiced per roll is short material you pay for; get both into the quotation.
- Joins — agree in writing the maximum per roll, whether joined rolls count toward the ordered length, and how each is flagged (edge tab or marker) so the operator sees it coming.
Winding direction and core
Winding direction and core must be specified, not assumed: they decide which face meets your process first and whether the roll goes onto your shaft.
One face is metallised or treated, the other bare; whichever winds out is what the print unit, adhesive station or laminating nip meets first.
- Face in or out — in protects the working surface in transit; out suits a coated-side-up first pass.
- Show it — A-wind and B-wind conventions vary between plants, and “coated side up” still fails when the roll can load from either side of the stand; attach a labelled sketch or photo of a roll on your unwind, up face and web exit marked.
- Core inner diameter — commonly 76 mm (3 inch) or 152 mm (6 inch); it must match your shaft or chuck, or the job stops on arrival.
- Core material, wall, position, return — paper or plastic; a wall that will not collapse under a heavy roll; flush with the film edge or protruding for chucking; whether cores go back.
Packing and long storage
Packing should protect the edges and the wound face first, and the right method depends on the construction, so agree it, pallet or floor-loaded, rather than accept a default.
- Wrap and ends — inner wrap plus end caps or core plugs keeps dust and knocks off the wound face.
- Thin metallised film — wide, heavy rolls often ship standing on end boards or core-suspended in a crate to avoid flat spots; lighter rolls go horizontal on cradles.
- Foil-bubble, foil-foam and woven laminates — light and bulky, typically bagged and shipped horizontal; on end they load the bottom edge for no gain.
- Long storage — the vapour-deposited aluminium on metallised PET is very thin and can grey out or pinhole with moisture and handling, and bare foil can corrode in humid storage, so keep unlaminated metallised film and open foil faces sealed in their inner wrap until the roll goes on the machine. Rolls off bare concrete, never stacked on rolls, anything opened rewrapped; ask the practical storage window for adhesive-bearing constructions.
Putting the width in the enquiry
Send the construction, end use, width band, binding roll limit and whether you can use a second width; where a nearby width yields better, we will show it alongside the one you asked for, so you see the difference before committing.
Send us the width band, your roll and core limits and what the film has to do. The companion checklist, how to specify reflective roll goods, covers the rest.