What Are Spray Caps
Aerosol can caps are technical nozzles that define a can's spray type. Each spray cap is engineered with a specific internal geometry that interacts with the valve to control the shape and power of the output. They are made from solvent-resistant plastic polymers to ensure structural stability. The technical difference lies in the outlet channel's diameter: a narrow opening generates a precise, controlled stroke, while a wide one maximizes output for fast fills, directly impacting speed and paint consumption.
How Spray Caps Work
The technical principle of a spray cap is straightforward: pressure on the cap opens the valve, forcing the paint and propellant mixture into the internal duct where atomization occurs. This duct's design defines the performance. The best caps for outlines, like the Pro Skinny, use a long, narrow duct for a compact, clean stroke. Conversely, fat caps have a short, wide duct that maximizes volume. The colored dot isn't an aesthetic detail but a technical identifier indicating the approximate stroke width. Compatibility is key: male caps (with a stem) must fit into the can's female valve (the hole). An incorrect fit causes leaks or overkill—an uncontrolled, massive release of paint.
Fat Spray Caps for Fast Fills
Fat caps are engineered for a single purpose: maximum output in the shortest time. This makes them the standard tool for bombing and large-scale fills, like panels or whole cars, where speed is the decisive factor. Their effectiveness comes from a wide outlet channel that ensures a massive paint output, capable of covering a surface in fewer passes. The result is a wide, saturated stroke, ideal for full and uniform fills. Among the benchmark models, the Pink Dot Fat is the standard for its powerful and clean spray. The New York Fat offers a denser, more controlled stroke. For the most demanding jobs, the Hardcore Fat and the Yellow Fat provide even greater output.
Skinny Spray Caps for Detailing
As the technical opposite of fat caps, skinny caps are precision tools designed for maximum control. Their design is based on a thin internal channel that constricts and slows the output, generating a fine, concentrated stroke. By creating sharp lines with minimal overspray—the halo of atomized paint at the edges of the stroke—they are considered the best caps for outlines. These features make them indispensable for outlines, details, and highlights, improving the quality of the work and optimizing paint consumption. The Banana Skinny is an excellent all-rounder, a versatile cap that balances fineness and output, suitable for both outlines and small fills.
Special & Ultra-wide Spray Caps
Night Quill has developed a series of caps with unique performances. The Vortex Halo, for example, is engineered to create a 60-cm-wide circular halo, an effect impossible to replicate with traditional caps. The range includes caps for ultra-flat spray fan or near-surgical details. Beyond these, other special caps exist, like the Calligraphy Cap, with an adjustable slit-shaped outlet that produces a flat stroke perfect for tags. The Stencil Cap is a masking accessory that fits over a skinny cap: a shield with a pinhole aperture that blocks most paint and channels a tiny jet, producing ultra-fine strokes down 2 mm.
Spray Caps & Valve Compatibility
Technical compatibility between spray can nozzles and the can's valve is a critical factor. Most European Graffiti Spray Cans use a "female" valve system (a hole), which requires "male" caps (with a stem), now the industry standard. However, some cans, typical of certain American brands or ultra-wide cans like MTN Mad Maxx, have "male" valves (a protruding stem). These require "female" caps, like the Night Quill Vortex Halo Female. Verifying the valve/cap system is fundamental to avoid incorrect fitting and leaks. A correct match ensures a hermetic seal and optimized performance.
Iconic Caps in Graffiti Writing
In the graffiti caps arsenal, some models have become a de facto standard. The Astro Fat is known for its devastating output: it has the widest possible spray among standard caps, sacrificing precision for extreme coverage. At the opposite end, the Pro Skinny is the standard for surgical precision, capable of tracing ultra-thin lines. Between these, the Lego Cap is a versatile medium, perfect for thick outlines and controlled fills. Finally, the Orginal cap, the stock cap on many European cans, is valued for its "dirty" and old-school stroke, a technical choice for an authentic aesthetic.
Cleaning and Reusing Spray Caps
Proper maintenance extends the operational life of spray caps. Clogging is caused by dry paint in the internal channel. For immediate cleaning after use, simply turn the can upside down and spray until only gas comes out. This action purges the channel of fresh residue. For a deeper clean or for already clogged caps, using a specific solvent like Montana PRO Solvent is the most effective solution. Unlike gas alone, the solvent actively dissolves paint residue, restoring the internal channel. It is crucial not to use sharp objects to clear the hole, as they could damage the internal geometry, permanently altering the stroke.
