You are not buying fabric, you are buying yarn by the kilogram

The line that does not exist

Course 8.1 builds a cost sheet from a bill of materials, and the first line of it is fabric: a consumption in metres or in kilograms, taken from a marker, multiplied by a price. A marker is the cutting plan that shows how the pattern pieces sit on the cloth. Course 8.2 buys that fabric against a minimum order quantity and a clock.

On KV-2280 there is no marker, no width, no metre and no fabric. Nothing is cut. The panels come off the needles in the shape they will keep, and the only material the factory ever buys is yarn on cones, priced by the kilogram. That one difference puts three lines on the cost sheet that a woven sheet has no column for. Every one of them is worth more than the argument the merchandiser usually has.

Where the weight comes from

You cannot calculate the weight of a sweater from first principles in a way anyone will accept. You knit it, finish it, and put it on a scale.

Rangdhanu's method has four steps. Knit the full panel set on the approved program. Make it up. Scour, soften and tumble it exactly as the bulk will be treated. Condition it for 24 hours, then weigh it. What comes off that scale is the finished weight of one size in one colour, and that is where the first error lives.

The weighted average is 0.341 kg. The sample that was weighed was a size M at 0.323 kg, because size M is what the buyer fits on.

Cost the order on the sample and you understate the yarn by 0.02 kg a garment. At USD 21.20 a kilogram that is USD 0.42 a sweater and USD 7,560 on the order. On a margin of USD 3.05 a garment, it is fourteen per cent of the profit, taken by a step nobody thinks of as a step.

A woven garment does not fail this way. A marker is made for every size, so the size ratio is already inside the way consumption is calculated. A sweater has no marker. Somebody has to remember to apply the ratio, and on a first order for a new buyer there is often nobody whose job that is.

The waste factor, built rather than borrowed

Finished weight is what leaves. Yarn issued is what you buy. The gap between them is not a rule of thumb. It is four separate things, and a factory that cannot name them is quoting somebody else's number.

So yarn issued is 0.341 multiplied by 1.11, which is 0.3785 kg, and the order needs 6,813 kg.

Two things about that number are not true of a fabric consumption. The first is that the waste is much larger. Three per cent is a normal cutting allowance on a woven garment; eleven is normal here, because every one of those four rows is a knitting-floor event with no equivalent on a cutting table.

The second is worse. Dyed sweater yarn cannot be sold on. It is a count, a fibre and a colour that this buyer chose, and once it is dyed there is no second customer for it. Over-buy woven fabric and you have a roll. Over-buy sweater yarn and you have a write-off.

The kilogram you are invoiced is not the kilogram on your scale

Halsteen Spinning's invoice for the Loden colour states a weight. The store's scale reads a smaller one, and the storekeeper's first assumption is that somebody has short-delivered.

Yarn is traded on commercial mass, not on whatever the cones happen to weigh on the day they arrive. The consignment is sampled and dried until its mass stops falling. Then the moisture allowance agreed in the contract is added back to that oven-dry weight. For worsted wool yarn the long-standing trade allowance is 18.25%. It belongs in the contract, and a contract that does not state it has left the argument open.

The arithmetic on this order: 6,813 kg invoiced implies an oven-dry mass of 5,761 kg. Received into a store at a dry 45% relative humidity, wool sits nearer 12% regain, so the scale reads about 6,453 kg. Regain is the weight of water the fibre carries, as a percentage of its dry weight. The gap is 360 kg, or USD 7,632 of yarn that is not missing and is not there.

The dye lot is the unit, and it is smaller than the order

Sweater yarn is dyed before it is knitted, so colour arrives in lots. A package dyeing machine holds a fixed range of weights, and course 3.2 gives the sizes. Rangdhanu's dyer works between 400 kg and 800 kg to a lot.

Two consequences follow, and both of them are money.

Deep Ink cannot be bought. The colour needs 341 kg and the smallest lot the dyer will run is 400 kg. The order buys 400 kg, knits 341 kg of it, and writes off 59 kg of dyed lambswool at USD 21.20. That is USD 1,251, spread over 900 garments, or USD 1.39 each. On an FOB price of USD 17.60, that one colour carries an extra eight per cent of its own price because of a number in the dyehouse. It is not a reason to refuse the colour. It is a reason to price it separately, or to ask the buyer for 1,060 pieces instead of 900 so that the yarn is not thrown away.

Loden runs in four lots, and a sweater is not piece-dyed. On a woven garment the cloth is dyed in the piece, so a lot change is a roll change and it is caught at the cutting table. Here the colour is in the yarn, so two lots can meet inside one garment — a body from lot 2 and a sleeve from lot 3. No light box at final inspection will save you, because by then the garment exists.

The control is upstream and it is boring. Cones are labelled by lot at the dyer, kept by lot in the store, and issued by lot to a machine. A panel set is finished from one lot before the machine is fed again. Every knitwear factory says it does this. The ones that actually do it have a lot number written on the panel bundle ticket.

The sheet, rebuilt

Yarn is 55% of the cost of this garment. That ratio governs every decision in the rest of this course. At that share, one percentage point of yarn waste is worth more than one percentage point of anything else on the sheet, and a construction that saves labour by spending yarn is almost always the wrong trade. Lesson 3 puts a number on exactly where "almost always" stops being true.

Act as a knitwear costing manager. I need a sweater cost sheet built the way knitwear is actually made, and then a construction decision that falls out of it. Facts: buyer [BUYER], style [STYLE], quantity [QTY], FOB [PRICE], gauge [GAUGE], fibre and yarn count [SPEC], yarn price per kilogram [PRICE], size ratio [RATIO], colour split [COLOURS AND QUANTITIES]. My dyer's minimum and maximum lot sizes are [KG] and [KG]. My rates: machine-hour [AMOUNT], linking [AMOUNT] an hour, general making up [AMOUNT] an hour. Knitting minutes a panel set [NUMBER]. Linked edge length [CM]. Cutting utilisation if I knit blanks [PERCENT]. Do the following. First, take the finished garment weight ACROSS THE SIZE RATIO rather than from the sample size. Show me both numbers and the difference in dollars on the order. Second, build a waste factor from named sources: set-up and trial panels, panels rejected at the machine, mending and garment rejects, and cone tails. Give me the yarn issued per garment and for the order. Third, work out how many dye lots each colour becomes, flag any colour whose quantity is below the dyer's minimum, and price the dead yarn per garment for that colour. Fourth, build the full cost sheet to a total, a margin per garment and a margin percentage, and tell me what share of the cost is yarn. Fifth, cost the same garment as fully fashioned, as cut and sew, and as whole garment, and give me the yarn price per kilogram at which fully fashioned and cut and sew cross. Sixth, say which route my yarn price implies, and what would change the answer. Never put a fabric consumption in metres anywhere in this sheet.