C47

C47

noun | Production & On-Set

Film and television crew slang for an ordinary wooden spring clothespeg — the type used for hanging laundry on a washing line. On a film set, C47s are used as a universal low-tech fastener: attaching colour correction gels and diffusion materials to the barn doors and frames of lighting fixtures, securing cables, holding items in place, marking positions, and dozens of other improvised applications. The C47 is one of the most used items in the grip and electric departments' expendables kit and is typically carried in large quantities in every lighting truck.

Quick Reference

The Explanation: How & Why

The clothespeg is one of film production's most useful tools precisely because it is cheap, widely available, heat-resistant enough to handle lighting gels, easy to apply and remove with one hand, and strong enough to hold lightweight materials in place against gravity and air movement. No purpose-designed alternative has displaced it because nothing works better for its specific application.

Primary use — attaching gels to barn doors:

Lighting fixtures have adjustable metal flaps called barn doors that can be positioned to control the spread and direction of the light output. When a gaffer needs to add a colour correction gel (CTB, CTO, CTS) or a diffusion material to a fixture, the simplest method is to clip the gel or diffusion to the barn door using C47s. The spring clip of the clothespeg grips the edge of the barn door on one side and the edge of the gel or diffusion on the other, holding the material in place firmly. The wooden construction of the C47 provides sufficient heat resistance for the gels on most tungsten and HMI fixtures — it will char and eventually burn at very high temperatures, but for typical fixture use it is durable enough.

Why the name "C47":

The origin of the name is one of film industry folklore's more entertaining stories. The standard account is that gaffers and best boys were reluctant to admit they were using ordinary clothespegs — a mundane domestic item — as professional equipment on expensive film productions. Calling them by a technical-sounding designation ("C47") gave the item a veneer of professional specificity. The "C47" designation is sometimes said to appear on actual supply catalogs, though the item being ordered is unmistakably a spring clothespeg. The name is now so established in professional use that most working gaffers have never thought to question its origin.

Alternative accounts suggest "C47" is simply a catalog code that stuck. Whatever the origin, the name is universal on English-language film productions — ordering "a box of C47s" is as standard a professional request as ordering gaffer tape.

Secondary uses:

C47s find applications wherever a small, strong clip is useful on set:

• Securing trailing cables to stands or frames so they do not hang loose in frame
• Holding lightweight set dressing items in place
• Marking actor positions on costumes (a C47 on a specific seam marks where a performer was standing for continuity)
• Holding script pages or call sheets conveniently accessible on equipment
• Clipping diffusion to reflector frames

The C47's versatility means virtually every department on a film set has a handful on hand.

How many to carry:

The electric department typically carries hundreds of C47s in their expendables kit. On a day with many lighting setups involving gels and diffusion — an interior location with multiple sources being colour-corrected — a single gaffer might use 30-50 C47s over the course of the day. They are cheap enough that they are never rationed; running out of C47s on set would be an embarrassing logistical failure.

Historical Context & Origin

The clothespeg has been used in film production since at least the sound era — any production using gel on a lighting fixture faced the practical problem of how to attach it, and the spring clothespeg was the simplest available solution. The "C47" designation appears to have emerged through the studio system as a way of assigning a professional catalog designation to an item purchased from domestic supply sources. The name is now so standard that it is the term used in crew conversations, on equipment orders, and in training for new electric and grip department crew.

How It's Used in Practice

Scenario 1 -- Attaching Gel (Best Boy Electric / Gaffer): The gaffer asks for full CTB on the 2K fresnel in the background. The best boy cuts a piece of CTB gel to fit the barn door and clips it to the top and bottom of the barn door using two C47s. The gel is secure, flat against the barn door, and the fixture can be aimed and adjusted without the gel falling off. Setup time: forty-five seconds.

Scenario 2 -- Diffusion Attachment (Gaffer): A large bounce card with a diffusion frame is being set up in front of a 4-foot HMI. The diffusion material needs to be attached to the frame without wrinkles. The gaffer clips the diffusion to the frame's edges using six C47s at even intervals, ensuring it sits flat and taut. No purpose-built system would be faster or simpler.

Scenario 3 -- Improvised Use (Grip): During a shot, a small prop — a piece of paper — keeps moving in the air conditioning draft from the set's ventilation. A grip reaches into their pocket, where they always carry a handful of C47s, and clips the paper's corner to the table surface. Problem solved in ten seconds with a clothespeg.

Usage Examples in Sentences

"Give me two C47s on that CTB — it is starting to fall off the barn door."

"Box of C47s on the electric truck, left door, lower shelf. We need them on the set now."

"It is a clothespeg. It costs three cents. It is the most useful thing in the kit."

"The first time you work on a real set and somebody asks you for a C47, and you know it is a clothespeg — that is how you know you are in the industry."

Common Confusions & Misuse

C47 vs. Alligator Clip: An alligator clip (or crocodile clip) is a metal serrated spring clip used in electronics and sometimes on sets for specific applications. It is not a C47. The C47 is specifically a wooden spring clothespeg. Alligator clips are used on electrical connections and for specific rigging applications; C47s are used for attaching soft materials (gels, diffusion) to fixture hardware.

C47 vs. Gaffer Tape: Both are used to attach materials to set and fixture hardware, but through different mechanisms. Gaffer tape uses adhesive and is destructive to surfaces it is applied to and removed from; a C47 uses mechanical spring pressure and is completely non-destructive. Gels are typically clipped with C47s rather than taped because tape leaves adhesive residue on fixture barn doors and gel material.

Related Terms

• Expendables -- The category of consumable supplies that includes C47s; they are one of the most-used items in the expendables kit
• Gel -- The primary material that C47s are used to attach to lighting fixtures
• Diffusion -- Another material attached to fixtures using C47s; frost, silk, and diffusion gel all benefit from C47 attachment
• Gaffer -- The lighting department head who most frequently uses and requests C47s on set
• Grip -- The department that also carries C47s for their own rigging and attachment applications

See Also / Tools

The Shot List Generator is indirectly relevant — each lighting setup on the shot list that involves gels or diffusion on fixtures requires C47s. A detailed shot list showing the number of lit setups allows the electric department to estimate C47 consumption for the production.