Day 15: What is "Cutable Width"? (Why 60" isn't 60")

Welcome to Week 3, Day 15 of My Dad vs. The Algorithm.

Today we are talking about The Edge of the Roll.

A designer recently emailed my dad, Ira, in a panic. They bought 500 yards of fabric listed as 60 inches wide. They made their marker (the cutting layout) exactly 60 inches wide.

When the cutting room rolled out the fabric, the edges of the pattern pieces were falling off the fabric or hitting glue lines. The designer asked: "The receipt says 60 inches. Why can't I use all 60 inches?"

Stay in the lane! 🚗 Just because a fabric roll says "60 inches wide" doesn't mean you have 60 inches of drivable road.

Ira’s Reaction:

"You don't drive your car on the shoulder of the highway, do you?The edge of the fabric is for handling, not for cutting. It has pinholes, glue, and curl. You have to stay in the lane. If the roll says 60, you only have 58 inches of drivable road."

Here is the difference between Gross Width and Cutable Width.

The Anatomy of the Edge (Selvedge)

When fabric goes through the finishing process (the stenter frame), it is held open by pins or clips. To keep the edges from curling up, we often apply a thin line of stiff glue (gumming).

This creates a Selvedge—the messy border of the fabric.

• Pinholes: Tiny punctures where the machine held the fabric.

• Gum Lines: Stiff, hard residue that you cannot sew through.

• Curl: The natural tendency of knit fabric to roll up at the edges.

The "Minus Two" Rule

If a mill tells you the fabric is 60 inches, that is the Gross Width (from tip to tip). However, you cannot put your pattern pieces on the gum line or the pinholes.

You must calculate the Cutable Width. The industry standard rule of thumb is to subtract 2 inches from the total width.

• Gross Width: 60"

• Cutable Width: 58"

Ira’s Take:

"Don't get greedy with your marker. If you try to squeeze your pattern all the way to the edge to save money, you're going to end up with t-shirts that have glue in the side seams.Save yourself the headache. Assume you have 2 inches less than what the ticket says."

Tubular vs. Open Width

This rule applies differently depending on the format:

1. Open Width: The fabric is flat. You lose ~1 inch on the left and ~1 inch on the right. (Total loss: 2 inches)

2. Tubular: The fabric is a tube. There are no "edges" in the middle, but the crease lines on the side might need to be steamed out or avoided depending on the fabric.

The Bottom Line

When planning your production, never plan for the best-case scenario. Plan for the reality of manufacturing.

• Ask the mill: "What is the Cutable Width?"

• Tell your pattern maker: "Stay 1 inch away from the edge."

Ira’s Final Advice:

"The edge is the crust of the pizza. It's there to hold the slice together, but you don't put the pepperoni on it. Keep your pattern in the center."

Tune in tomorrow for Day 16!

(Missed yesterday's post about Organic Cotton? Read Day 14: The Organic Myth here.)

Need specs you can trust? All our Online Stock lists Cutable Width clearly.