This guide shows the level of technical detail a Brand Library needs so Pencil generates work that is on-brand from the first draft. The Brand Library is where a brand's rules, assets, and tone are defined once, then applied automatically across every brief, agent, and output. The richer and more specific the inputs, the less editing teams do downstream.
Vague inputs produce generic output. Specific inputs produce on-brand output.
Aim for rules a new team member could follow without asking a question. If a field could be read two ways, it is not specific enough yet.
What are the eight essential building blocks a Brand Library must contain?
A Brand Library is strongest when these eight areas are filled in with real specifics rather than placeholders. Each one shapes a different part of what the agents produce.
1. Logo and lockups
Files: primary logo, secondary or stacked lockup, and icon or symbol, each in vector (SVG) plus high-resolution PNG with transparent background.
Variants: full-colour, all-black, all-white or reversed, for use on light and dark backgrounds.
Clear space and minimum size: the exclusion zone around the logo and the smallest size it may appear.
Misuse: what is not allowed, for example stretching, recolouring, adding effects, or placing on a busy background.
2. Colour
Primary palette: each colour with HEX, RGB, and where relevant CMYK and Pantone values.
Secondary and accent colours: with the same values and a note on when each is used.
Usage ratios: rough proportions, for example a dominant neutral with a single accent, so output does not overuse a bright colour.
Contrast and accessibility: approved text-on-background pairings that meet legibility standards.
3. Typography
Typefaces: primary and secondary families, with the specific weights that are licensed and permitted.
Hierarchy: how headings, subheadings, body, and captions differ in size and weight.
Rules: line length, letter spacing, and any pairing that is not allowed, for example two display faces together.
4. Voice and tone
Voice attributes: three to five adjectives that describe how the brand sounds, each with a one-line explanation.
Do and do not: words and phrases to use, and ones to avoid.
Register by context: how tone shifts between, say, a product ad and a support message.
Worked lines: one on-brand sentence and one off-brand sentence, so the difference is unambiguous.
5. Imagery and art direction
Style: photography, illustration, 3D, or a defined mix, with reference examples.
Treatment: colour grading, crop style, use of negative space, and any filters or effects.
Subject and composition: what is shown and how it is framed, including people, product, and environment.
Off-limits: visual styles or subjects the brand never uses.
6. Layout and graphic elements
Grid and spacing: the spacing scale and margins that keep layouts consistent.
Signature elements: any recurring device such as a shape, line, or motif that signals the brand.
Component styles: buttons, cards, and framing where they apply to output.
7. Messaging and claims
Core lines: tagline, value proposition, and any approved boilerplate.
Product and feature names: exact spelling and capitalisation, so names are never rendered incorrectly.
Claims and disclaimers: statements that are approved, and any legal wording that must appear.
8. Compliance and market rules
Regulatory lines: mandatory disclaimers or restricted wording by category or region.
Market variations: differences in language, spelling, or claims across the markets the brand operates in.
Approvals: who signs off, so the right review step is built in rather than bolted on.
How specific each field should be
This table sets the bar for detail. The middle column is the standard to aim for. The right column explains what changes in the output when the field is done well.
Brand Library field | What good looks like | Why it matters to output |
Primary colour | #1A1A1A with RGB, plus a note: dominant on 70% of surfaces | Prevents washed-out or off-palette results and keeps a consistent feel |
Accent colour | #FFE234 used for one highlight per layout, never for body text | Stops bright colours being overused and keeps emphasis meaningful |
Heading font | Geist, weights 500 and 700 only; no italic | Type stays licensed and on-system across every asset |
Voice | Direct, confident, human. Short sentences. No jargon. | Copy reads like the brand, not like a generic model |
Do-not words | Avoid: "revolutionary", "seamless", "game-changing" | Removes hype the brand has chosen not to use |
Imagery | Natural-light photography, real settings; no flat stock or heavy filters | Visuals match the intended look instead of defaulting to stock |
Product names | Exact casing, e.g. product names capitalised as registered | Names render correctly every time, protecting the brand |
Disclaimer | Mandatory legal line, exact wording, placed on all paid assets | Compliance is built in, reducing rework and risk |
A Worked Example of a well-completed Brand Library
Below is an illustrative, fictional brand (Northwind (illustrative example)) completed to the standard this guide describes. It is a model to compare a real setup against, not a template to copy. Values are invented for demonstration.
Colour
PALETTE Ink #14212B RGB 20 33 43 dominant neutral, ~70% of surfaces Signal #FF5A3C RGB 255 90 60 single accent, one highlight per layout Paper #F6F4EF RGB 246 244 239 background and space Text on Ink must be Paper or white. Signal is never used for body text. |
Typography
Display: a single grotesque family, weights 500 and 700. No italic, no third weight.
Body: the same family at weight 400, 16 to 18px equivalent, line length 60 to 75 characters.
Not allowed: pairing the display face with any second display font.
Voice and tone
Attributes: plain-spoken (say it simply), assured (no hedging), warm (write to a person, not a segment).
SAMPLE COPY On-brand: "Set it up once. It stays right every time." Off-brand: "Leverage our seamless solution to revolutionise your workflow." |
Imagery
Style: natural-light photography in real workspaces; people mid-task, not posed.
Treatment: minimal grade, true-to-life colour, generous negative space; no heavy filters or vignettes.
Never: flat corporate stock, glossy 3D renders, or busy collages.
Messaging and compliance
Value line: "On-brand work, without the back-and-forth."
Feature names: written exactly as registered, with fixed capitalisation.
Mandatory line: an approved disclaimer appears on all paid placements, exact wording locked.
A note on Pencil's Open Garden approach: because the Brand Library sits at the centre and every agent and model reads from it, one well-built set of rules governs output across the whole workflow. The work you put in here is applied everywhere, automatically.
Quick checklist to run through before you save!
Logo files supplied in vector plus PNG, with colour, black, and reversed variants
Every colour has HEX and RGB, with usage notes and a dominant neutral identified
Fonts named with permitted weights, and any disallowed pairing stated
Voice captured as attributes plus an on-brand and off-brand example
Imagery defined by style, treatment, and a clear off-limits list
Product and feature names spelled and capitalised exactly
Mandatory legal or market wording included, with placement noted
A colleague unfamiliar with the brand could produce on-brand work from these inputs alone