Day 13: What is a "Fabric Lot"? (And Why You Can't Always Get 1,000 Yards)

Welcome to Week 2, Day 13 of My Dad vs. The Algorithm.

Today we are doing some "Dye House Math."

A customer emailed my dad, Ira, frustrated because they ordered 1,000 yards of our Heavyweight French Terry from stock, but they received two different lot numbers. They wanted to know: "Why couldn't you just give me 1,000 yards from one single lot?"

Buying off the shelf? You might get a mix of Lot A, Lot B, and Lot C. 🎲 If you need consistency for a large order, submit a Production P.O. so we can run it all together.

Ira’s Reaction:

"Because a dye machine isn't a magic portal; it's a metal tank. It has a physical limit. You can't fit a gallon of milk into a pint glass. If the machine only holds 600 yards of heavy fabric, that's the lot size. Physics doesn't care about your Purchase Order."

Here is the breakdown of how Fabric Lots work in Los Angeles manufacturing.

The Rule of 20: The Machine Limit

In our Los Angeles dye houses, a standard industrial jet dye machine typically holds about 20 to 25 rolls of fabric at a time. Everything that goes into that one machine at that one time is considered One Lot.

Because the machine capacity is fixed by volume (how much space the fabric takes up), the yardage you get depends entirely on the weight of the fabric.

The Weight Math: Light vs. Heavy

This is where the math gets tricky. Heavier fabric takes up more space, meaning you get fewer yards per lot.

• The Lightweight Example (9oz Jersey):

  • Since the fabric is thin, we can fit more on a roll (~50 yards).

  • 20 Rolls x 50 Yards = ~1,000 Yards per Lot.

  • Result: You can easily get a big order in one lot.

• The Heavyweight Example (20oz French Terry):

  • This fabric is thick. A roll gets huge quickly, so it only holds ~30 yards.

  • 20 Rolls x 30 Yards = ~600 Yards per Lot.

  • Result: If you order 1,000 yards, you literally cannot get it in one lot. It physically requires two machine loads.

The Trap: Buying Stock vs. Planning Production

This is why buying "Stock" for large orders is dangerous.

If you buy from our "Stock List," you are buying whatever is sitting on the shelf. We might ship you 20 rolls (One Lot), and then the next 20 rolls we grab might be from a different dye batch from last week.

The Solution: The Production P.O. If you know you need 1,000+ yards, submit a Production Order. This tells us to plan ahead. We will:

1. Knit all the yarn from the same batch.

2. Dye the loads back-to-back on the same machines.

3. Control the variables so the transition between Lot A and Lot B is seamless.

The "Human Factor" (Why You Must Test Shrinkage)

Even if you place a production order and we dye 5 lots for you on the same day, you still need to test shrinkage for every single lot.

Ira’s Take:

"Fabric is made by humans and machines, not robots in a vacuum.One machine might have been 2 degrees hotter. One operator might have set the tension slightly tighter. That can change the shrinkage by 1-2%.Never assume Lot B is identical to Lot A. Cut a 10x10 square from every lot and wash it. If you don't, your Mediums might turn into Smalls."

The Bottom Line

Don't fight the physics of the dye house.

• Light Fabric = Larger Lots (~1,000 yds).

• Heavy Fabric = Smaller Lots (~600 yds).

Ira’s Final Advice:

"If you are ordering big volume, stop buying off the shelf. Give me a P.O. so I can make the lots match. If you buy random rolls, you get random results."

Tune in tomorrow for Day 14!

(Missed yesterday's post about Speed? Read Day 12: Price vs. Speed here.)

Ready to plan your production? Contact us to Start a Production Order.