When it comes to designing a graffiti piece that truly stands out, few details have as much impact as extensions. Used well, extensions in graffiti elevate your wildstyle, create flow, and enhance letter structure, but used poorly, they can break your piece entirely. In this full breakdown, we’ll walk through a complete blackbook session, from base sketch to final details, and show you exactly how to build your letters, first analyze the fundamentals, and then add extensions that support your art, rather than sabotage it.

Start with Structure: The Foundation Before Extensions

Before jumping into details, serifs, and extensions, start with base letter construction, no shortcuts. Begin by laying out basic boxes for each letter. This step is essential because your extensions depend on solid letter structure and positioning.

For this session, we began with the word “GRIM,” starting with a lowercase G:

The G has a large bowl on the left and a slanted stem on the right.
After realizing a low-hanging serif created excess negative space, we tilted the letter slightly and refined the boxes to reduce the space without losing balance.

Now I have to admit, while sketching, I did forget I was supposed just to use the base structure, then stylize it, so here we’ve bent the bottom of the G, and that’s too much style for a starting sketch. If you’re more experienced, then so be it, you can detail the letters as you go along, but if you’re looking forward to this tutorial, then you’d want to keep it a basic print font so that we can build off of it later.

The Piece: Designing Each Letter Logically

G — Bold Body, Room to Breathe

The G was built with deliberate volume on the left through its bowl. After adjusting the baseline slope and refining the tilt, the negative space between the bottom sections felt more controlled. We kept this letter well-anchored for later extension work and weight balancing.

R — Two-Box Leg & Structural Rhythm

Next came the R—a perfect playground for structure clarity:

We chose a two-box leg to create movement and flexibility, add weight, and create space.
The diagonal push on the leg created line alignment opportunities later with the I.

I — Connecting and Flowing

The I was built to flow between R and M:

Its structure used a subtle bend to mirror the R leg angle (line uniformity and similarity).
The tit of the I later helped tie the top of the I to the M, using orientation and alignment to create cohesion.

M — Bringing the Weight Back

With so much presence on the left side of the name, the M needed to pull weight to the right:

A tight center kept the M from becoming too wide.
The serifs and terminals were scaled deliberately to add letter weight without throwing off the balance.
Later, compressed extensions and stars helped add flow, depth, and 3D dynamism to the right-hand side.

Analyze the Fundamentals (Again and Again)

Throughout the entire sketch, we constantly asked questions about the graffiti fundamentals:

Letter Structure – Is each letter strong on its own?
Negative Space Management – Are any sections too empty or too crowded?
Letter Name Weight – Does the overall name feel balanced from left to right?
Positioning – Are the overlaps and placements clear, or are the letters too obstructed?
Flow – Do lines and shapes carry your eye smoothly through the piece? Do we have repeating elements throughout the image?

This is the key to building a successful piece, especially if you’re planning to add extensions: your extensions must serve the fundamentals, not override them.

Using Extensions in Graffiti: Purpose First, Style Second

Extensions are decorative by nature, which means they must support your sketch’s fundamentals. Here’s how the process looked in action:

Extension #1: Filling Negative Space on the G

We added an extension that flows out of the terminal of the G, runs along the form briefly, then descends to fill a gap beneath the letter.

Origin: Terminal of the G
Travel Distance: Short, aligned with existing structure
Destination: Fill specific negative space and add flow
Result: Clean, functional, and stylish—without overpowering the structure.

Extension #2: Matching the R to the G

To build uniformity, we echoed that same extension concept on the bottom right of the R, and used it to visually help hold up the I. This didn’t just unify the style, it made the I feel integrated.

Extension + Detail Cohesion: Stars and 3D Depth

To increase visual rhythm and 3D interest, we introduced stars across the piece:

Purpose: break up long lines, add variety, and improve 3D geometry
We added them in prime numbers (e.g., three) to keep visual balance.

Compressed Extensions vs. Larger Extensions

This sketch primarily used compressed extensions, short, powerful shapes that add utility without sprawling across the piece. They’re excellent for:

Filling specific gaps
Reinforcing line alignment
Enhancing 3D by adding depth and adding variety by breaking up long lines.

Strategic Line Alignment & Visual Cohesion

A big part of building great flow in graffiti is line and letter uniformity and similarity, repeating similar angles, curves, or motifs across letters. Examples:

The I’s bottom aligns with the M.
The G top serif and the M serif share designs.
The Stars, compressed extensions, and conventional extensions repeate through the piece.

We also used sliding structural elements (like moving the G’s bottom and M’s right sections) to make more room for details and improve the silhouette, a trick that’s far easier digitally, but still doable traditionally with some patience and an eraser.

Final Polish: Outline, 3D, and Color Concept

For the finishing touches:

We used a blue fade fill for a smooth color story.
The 3D used burgundy with a hint of purple for richer depth and tone.
A white outline created a torn paper aesthetic, reinforced by subtle pen-style doodles, a fun conceptual detail that matched the blackbook vibe.

Key Takeaways: How to Use Extensions the Right Way

Build your letters first. Strong structure makes strong extensions.
Use extensions with purpose. Fill space, add weight, enhance flow, or improve 3D, not just to decorate.
Work in motifs. Repeat extensions and details across the piece for cohesion.
Analyze fundamentals constantly. Structure, negative space, weight, positioning, flow, use them to guide decisions.
Be flexible. Don’t force details that don’t work. Let your sketch evolve.

Get the File + Learn More

Want to study the exact sketch? You can download the file (in multiple formats) for free HERE
If you’re serious about learning graffiti fundamentals, how to do extensions, structure, flow, and building your style from the ground up, check out our How to Do Graffiti book. It’s the only resource covering every fundamental in depth, with hundreds of illustrated examples for both beginners and experienced writers.

If you're unsure where to start or how to avoid common mistakes, check out our graffiti fundamentals book available online; it’s packed with real lessons and photos to guide your development as an artist.

Grab a digital copy here: Ultimate Graffiti Guide Book Part 1: Fundamentals

Complete Graffiti Process | Designing Extensions and Letter Structure