TesseraSeal · Communications Style Guide

TesseraSeal · Communications Style Guide · v1.0 · Locked 2026-05-08

The book of house rules.

Every mark, every colour, every typeface, every margin, every bullet, every word — articulated and proven by sample. Print and digital. Light and dark. The brand has earned a documented voice; this is it.

16 sections·54 rules·2 themes·4 typefaces

Contents

The brand voice01 The dual mark system02 Colour · Light + Dark03 Typography & ligatures04 Type scale05 Hierarchy & headers06 Bullets & lists07 Callouts & pull quotes08 Numerals, hashes, money09 Grids & spacing10 Components11 Print templates12 Digital templates13 Voice & copywriting14 Do / Don't gallery15 Asset library16

№01— the brand voiceThree principles, applied at every layer. If a design choice fails any of these, it fails.

PRINCIPLE I

Examiner-first.

Every artefact must be legible to a stranger reading it six years from now. If the audience is not "an examiner who has never met you," redraft.

PRINCIPLE II

Quiet authority.

No exclamation marks, no emoji, no gradients, no marketing slop. The brand earns gravity by being earned, not by being shouted.

PRINCIPLE III

Documented, not asserted.

Every claim ships with a hash, a chain ID, or a key fingerprint. Mono numerals carry the receipts.

№02— the dual mark system#32 (codex + halo) signs. #35 (dovetail + halo) markets. Never substitute one for the other.

Rule 02.1

#32 — the signing mark

Use anywhere the brand co-signs a document of record. Letterhead, audit cover, certificate, contract, regulator filing, email signature, running PDF footer.

TesseraSeal

Lead position on every paper artefact. Always paired with the wordmark unless < 24 px.

Don't

Use #32 in dashboard chrome, app icons, or marketing heroes — that's #35's job.

Rule 02.2

#35 — the category mark

Use anywhere the brand is being seen, evaluated, remembered. Marketing hero, conference banner, app icon, OG card, dashboard chrome, social.

TesseraSeal

Render large — the silhouette wants ≥ 25% of frame in hero compositions. Watermark at 8–10% opacity.

Don't

Crop the dovetail. The notch is the silhouette. If it doesn't fit, use #32 instead.

Rule 02.3

Clear space & minimum size

Clear space equals the height of the halo (V) inside the mark. Below minimums, drop the wordmark and use the icon mode.

Mark	Min · with wordmark	Min · icon-only	Clear space
#32	32 px / 12 mm	16 px / 6 mm	1 × halo height
#35	40 px / 14 mm	20 px / 8 mm	1 × halo height

№03— colour · Light + DarkTwo themes, six tokens. Apply by surface intent, not surface type. Oxblood for signing; gold for ceremonial.

LIGHT THEME · L1 · BOOKISH

★Light winner · 53.2%

Paper · Ink · Oxblood

Paper

F5F1E8

Ink

0E1620

Oxblood

6E1A1F

Token	Role	Use
--paper	Ground	page background
--ink	Figure	body type, rules
--oxblood	Accent	seal, links, hairline

DARK THEME · D1 · COVER

★Dark winner · 47.8%

Ink · Paper · Gold

Ink

0E1620

Paper

F5F1E8

Gold

B08642

Token	Role	Use
--ink	Ground	page background
--paper	Figure	body type, rules
--gold	Accent	medal, headlines, CTA

Rule 03.1

Surface intent, not surface type

Light is the signing theme. Dark is the ceremonial theme. A web page can be light if it's signing-mode; a print cover can be dark if it's a presentation.

Audit cover sheet (presentation) → Dark. Letterhead (signing) → Light. Even though both are paper.

Don't

Pick a theme just because the surface is a screen. The dashboard is dark because it's ceremonial; the email is light because it's signing.

Rule 03.2

Tertiary palette · sparingly

Navy, Moss, Bone are functional, not decorative. Each has a single specified use and may not be promoted to a theme accent.

Navy · regulator portals only

Moss · “● sealed” status

Bone · long-form docs only

Rule 03.3

Contrast minimums

All body type clears WCAG 2.2 AA at the specified weight. Oxblood on Ink is forbidden at body size — accent rules and dingbats only.

Pair	Contrast	Verdict
Ink on Paper	14.8:1	AAA · all sizes
Paper on Ink	14.8:1	AAA · all sizes
Oxblood on Paper	7.8:1	AAA · ≥ 11 px
Gold on Ink	5.4:1	AA · ≥ 14 px
Oxblood on Ink	1.6:1	FAIL · accent rules only

№04— typography & ligaturesFour typefaces, one job each. Ligature settings are part of the spec — not optional.

FAMILY 01 · DISPLAY + BODY

Fraunces — the house face.

Used for every headline, every body paragraph, every wordmark, every signature. Variable axes (opsz 9–144, weight 400–700, italic). Free under SIL Open Font License.

LIGATURES & STYLISTIC SETS · CALL-OUT

first · stamp · effect → first · stamp · effect

dlig Discretionary ligatures: st, ct connect on display only. Headlines > 32 px only.

ss01 Stylistic Set 01: alternative g with single-storey eye. Wordmark only.

SOFT SOFT axis at 60: gentler terminals for italic display. Already baked into the wordmark file.

font-family: "Fraunces", Georgia, serif;
font-feature-settings: "dlig", "ss01";
font-variation-settings: "SOFT" 60, "opsz" 96;

WEIGHT MAP

400Witnessed quietly.body · long-form

500Witnessed plainly.display · default

600Witnessed firmly.italic emphasis

700Witnessed loudly.avoid · banner only

i·500— bound.accent verb

FAMILY 02 · UI

Inter Tight — the UI face.

Used in product chrome, dashboards, navigation, in-app micro-copy. Never in long-form prose, never on a cover sheet, never in legal copy. Free under SIL OFL.

FEATURES · TURN ON

Feature	Use
tnum	UI numerals (counts, dates)
cv11	Single-storey `a` · optional
ss03	Lining figures · default
case	Case-aware punctuation

SAMPLE · DASHBOARD

Audit Attestation Q1 2026

14 runs · 612,915 events · sealed

● Sealed Replayable v3 · key

FAMILY 03 · DATA + LEDGER

IBM Plex Mono — the ledger.

Used for every hash, every chain ID, every timestamp, every key fingerprint, every meta caps eyebrow, every running footer. The voice of the receipt. Free under SIL OFL — embed freely in distributed PDFs.

FEATURES · ALWAYS ON

Feature	Effect · why
tnum	Tabular figures — ledger columns must align
zero	Slashed zero — disambiguates from O in hashes
ss02	Alternate `l` with foot — disambiguates from 1 / I
calt	Contextual alternates — cleaner punctuation flow

Crucial · tnum is non-negotiable. Mono numerals that don't align in tabular columns destroy the ledger metaphor. Set it at the body level.

DISAMBIGUATION TEST

0 O 1 l I
0x4f9a 2d8e
612,915

The five glyphs that ruin a chain hash if confused. Plex disambiguates all five.

FAMILY 04 · SOURCE CODE ONLY

JetBrains Mono — the source.

Reserved for code blocks, CLI screenshots, README exhibits, and inline code spans in the documentation panel. Tall x-height optimised for line-after-line reading. Free under Apache 2.0.

CODE LIGATURES · DISCRETIONARY

== != >= <= -> => :: ===

→ == != >= <= -> => :: ===

Rule 04.1 Ligatures ON in code blocks. Operators fuse for readability. Set font-feature-settings: "calt", "liga". Code visibly carries the operator semantics — this is the point.

Rule 04.2 Ligatures OFF in inline contract text. When code references appear inside legal prose, ligatures must be disabled — operators must read literally to a court.

SAMPLE · CODE BLOCK

from vidimus import Witness
witness = Witness(tenant="atlas")
async for evt in agent.run():
witness.observe(evt) # O(1)
seal = await witness.close()
assert seal.chain == "0x4f9a..."

№05— type scaleA modular scale of nine sizes. Every typographic element on every surface picks one.

D1Witnessed.96 / 96 px
Hero · Banner

D2Witnessed.64 / 67 px
Cover · Eyebrow

D3Witnessed.48 / 50 px
Page header

D4Witnessed quietly, page by page.32 / 35 px
Section header

B1Subhead — quiet authority.22 / 29 px
Subhead

B2Body, long-form. The default reading register at 16 / 25.16 / 25 px
Body · long-form

B3Body, captions and footnotes — small but readable.13.5 / 21 px
Caption

M1META · CHAIN ID · 0X4F9A 2D8E11 / 16 px
Meta caps

M2META · RUNNING FOOTER8.5 / 14 px
Footer mono

№06— hierarchy & section headersEvery page leads with an eyebrow + headline pair. Every section opens with a numeral + role + descriptor (the “triplet”).

EYEBROW · ALL CAPS · 0.18em TRACKED

Headline — Fraunces D3, with one italic verb.

Standfirst — Fraunces B2 italic, 16 px, opacity 0.85. One sentence, one breath, no hyperbole.

№04

— the section role

A descriptor sentence that earns the section. Never two sentences.

THE TRIPLET · NUMERAL · ROLE · DESCRIPTOR

Rule 06.1

One italic per line, maximum

Italic is the brand's gesture. It's also a meal. Reserve it for the verb — the moment of action.

Every run, witnessed.

Don't

Every run, witnessed, sealed.

№07— bullets & listsBullets are not generic. Five contexts, five different markers — each chosen to mirror the surface's voice.

Rule 07.1 · prose

Em-dash bullets in documentation

Em-dash, oxblood, single-line items. Reads like marginalia.

The chain root is computed at the close of the run, not on each event.
Key versions are one-way; rotate forward, never backward.
Replay is offline by design — the verifier never phones home.

DEFENCE · WHY EM-DASH, NOT EN-DASH, NOT BULLET, NOT HYPHEN

The em-dash earns its width.

— em-dash

— Replay is offline.

U+2014 · 1em wide · serif anchor

– en-dash

– Replay is offline.

U+2013 · 0.5em · ranges only

- hyphen

- Replay is offline.

U+002D · 0.3em · cli, csv

• bullet

• Replay is offline.

U+2022 · powerpoint slop

▸ chevron

▸ Replay is offline.

U+25B8 · ui chrome only

FOUR REASONS · IN PLAIN ENGLISH

It's a literary mark, not a UI mark. The em-dash belongs to prose — Dickinson, Twain, the New York Review. It signals "this is a book, read it slowly." A bullet (•) signals slide-deck. A chevron (▸) signals dashboard. Documentation is neither; it is a document, in the noun sense, and the marker should reflect that.
Width is meaning. The em-dash is 1em wide — the same horizontal mass as the body x-height. It announces an item without imitating speech. The en-dash (0.5em) is reserved by typographic convention for 2026–2032-style ranges; using it as a bullet creates ambiguity in any line that contains a date or page range. The hyphen (0.3em) is too narrow to read as anything other than punctuation inside the word.
Fraunces draws it well. The em-dash in Fraunces has bracketed terminals and sits at cap-height — not on the baseline. It harmonises with the body italic. The bullet glyph in most serifs is perfunctory; the chevron is a Wingdings escapee. The em-dash is the only marker that was designed alongside the rest of the family.
It survives plain text. Documentation will be excerpted into emails, regulator portals, court filings, archived PDFs, screen-readers. — renders identically in every one of those surfaces. The bullet character renders as a black box in many monospaced terminals. The chevron is missing from most legal-doc PDF subsets entirely.

WHEN TO USE THE OTHER FOUR

Marker	Permitted in
— em-dash	Documentation prose. Pull-quote attribution.
– en-dash	Numeric ranges only: 2026–2032, pp. 14–18.
- hyphen	Compound words and CLI flags: `--tenant`.
• bullet	Forbidden in documentation. Permitted only in marketing dot-separators between meta items.
▸ chevron	UI breadcrumbs only: Dashboard ▸ Atlas ▸ Run 4f9a.

The shibboleth · If you can't tell the difference between — and – in body copy, you are not the audience for our documentation. Examiners can. The buyer can. The mark stays.

ANTICIPATED OBJECTION

“The em-dash is associated with AI-written copy now. Won't readers code-switch and assume the page was generated?”

Answer. The AI association attaches to em-dashes inside sentences — the parenthetical “clause — clause — clause” tic. This guide does not use that pattern in body copy; we use the em-dash structurally, as a list marker, where its history is Victorian (Dickinson's fascicles), not LLM. Readers who notice the difference are flattering us. Readers who don't are not the buyer.

Rule 07.2 · UI

Mid-dot bullets in web & product chrome

A single mid-dot, gold or moss, with Inter Tight body. Tight gap (8 px).

Audit-grade receipts
HMAC-chained event logs
Six-year offline replay window

Rule 07.3 · cover sheets

Lower-roman in contents & covers

Latinate, formal, italic. Sets the cover-sheet voice from the table-of-contents page.

Cover & tenant identification
Examiner's note
Chain-of-custody summary
Per-run sealed receipts

Rule 07.4 · legal

Statutory (a) (b) (c) in legal

Plex Mono parens, body-weight serif text. Numerals must read as inline citations.

The Service shall produce a Sealed Receipt for each Agent Run;
The Sealed Receipt shall comprise the canonical event log, the HMAC chain root, and the key-version fingerprint;
Delivery is deemed complete upon emission of the chain identifier to the Tenant's archival endpoint.

Rule 07.5 · marketing

Two-digit mono numerals in marketing

Plex Mono digits, gold accent, used as a counter for stat blocks. Bullets are forbidden in advertising body copy — rewrite in prose.

Witness every event in the run.

Seal the chain on close.

Replay six years from now.

№08— callouts & pull quotesThree callout shapes. Each carries a different urgency.

NOTE · 3PX GOLD RULE

A note callout — soft, parenthetical. The reader can skip without losing the thread.

REQUIRED · OXBLOOD CARD

YOU ARE ABOUT TO SEAL

A required callout — bordered, oxblood. Used at points of irreversible action: signing, sealing, exporting.

PULL QUOTE · BORDER-TB

“Oxblood on cream looks like a stamp on a deed. I would sign that.”

CCO · regional bank · 14 yrs

№09— numerals, hashes, moneyPlex Mono carries every figure. Three patterns cover the brand's numeric vocabulary.

PATTERN A · CHAIN HASH

0x4f9a 2d8e c81e 7b00

4-character groups, single space, never wrapped mid-group. tnum + zero + ss02.

PATTERN B · COUNT

612,915

Localised thousands separator, never abbreviated to “612K.” Receipts deserve the full count.

PATTERN C · DATE / SEQ

2026-03-15T09:14:02Z
seq 18,402 / 612,915

ISO 8601, UTC, always Z-suffixed. Sequence pairs use forward slash, no decimal.

№10— grids & spacingAn 8 px base unit. Twelve-column web; six-column print. Margins are generous; a margin is a virtue.

Token	Value	Use
--space-1	8 px	baseline · gap between intra-component items
--space-2	16 px	between paragraphs
--space-3	24 px	between component clusters
--space-4	32 px	section starts on screen
--space-6	48 px	section breaks on print
--space-8	64 px	page margins on cover
--margin-letter	56 px / 14 mm	letterhead all sides
--margin-cover	72 px / 18 mm	audit cover sheet

№11— componentsButtons, badges, tables, cards. Each has one canonical form; variants exist by theme only.

Rule 11.1

Buttons

Sharp corners, all-caps mono label, 10 px tracked. Primary fills; secondary outlines. No rounded corners ever.

Read the spec See it verify →

Rule 11.2

Badges & status pills

Border-only. Plex Mono 9 px caps. Status dot uses moss for sealed, gold for pending, oxblood for failed.

● Sealed ○ Pending ⚑ Failed v3 · key Replayable

Rule 11.3

Cards

Flat fills, no rounded corners, no drop shadows in print. On screen, cards may have a long ambient shadow (offset 0 / blur 80 / -30 / 50% black).

RUN · ATLAS-PAC-PROD

612,915 events · chain intact

0x4f9a 2d8e c81e 7b00 · sealed 2026-03-15

Rule 11.4

Tables

Mono headers (8.5 px tracked caps), italic serif body, dashed inner rows, solid header underline. Tabular numerals are non-negotiable.

Chain	Tenant	Events	Status
0x4f9a 2d8e	atlas-pac-prod	612,915	● sealed
0x9b21 4cf7	atlas-pac-prod	428,910	● sealed
0x2f10 8a4d	northrail-stage	92,431	● sealed

№12— print templatesLetterhead, audit cover, certificate, invoice, contract clause. Always Light theme except the cover.

LETTERHEAD · LIGHT · L1

TesseraSeal

228 Cannery Row, Suite 4A
San Francisco, CA 94133
tesseraseal.io

15 March 2026 · Reference TS-2026-0418-A

Atlas Pacific Bank, N.A.
Office of the Chief Risk Officer

To the addressee,

This letter accompanies the enclosed Audit Attestation Package for the period ending 28 February 2026, comprising fourteen (14) chain-sealed agent runs and the corresponding HKDF key-fingerprint disclosure.

Sealed · Witnessed · Replayable

chain · 0x4f9a 2d8e

COVER SHEET · DARK · D1

AUDIT ATTESTATION PACKAGE

The witnessed quarter,
bound.

Fourteen agent runs. Six hundred eleven thousand events. Bound into one ledger.

TesseraSeal

tenant atlas-pac-prod
0x4f9a 2d8e c81e 7b00

№13— digital templatesWeb hero, dashboard chrome, OG card, app icon. Always Dark theme except the in-app modal layer.

TesseraSeal

ProductVerifierComplianceDocs

Request access

AUDIT-GRADE RECEIPTS FOR AI AGENTS

Every run, witnessed.
Every record, sealed.

Six hundred eleven thousand events. Fourteen runs. One unbroken HMAC chain.

Read the spec See it verify →

tesseraseal.io

Every run, witnessed.

Audit-grade receipts for AI agents. Replayable line-by-line.

APP ICON · FAVICON · PROFILE

The dovetail-and-halo silhouette. Wordmark drops below ~24 px.

№14— voice & copywritingA short list of patterns you may use; a longer list of phrases that are forbidden.

PERMITTED · WRITE LIKE THIS

“Witnessed by Vidimus. Sealed by TesseraSeal.”

“Replayable, six years from now, by an examiner you haven't met.”

“Six hundred eleven thousand events. One chain.”

“The witnessed quarter, bound.”

FORBIDDEN · NEVER WRITE

“Revolutionary AI compliance!”

“Unlock audit-grade insights 🔐”

“The future of AI accountability is here”

“Powered by next-gen blockchain”

RULES OF THUMB

Numbers are receipts. Never round, never abbreviate.
Verbs are gestures. Witness · seal · bind · replay · attest. One per sentence.
Time is named. Always say “six years” or “Q1 2026,” never “forever” or “ongoing.”
The buyer is an examiner. Write to a stranger reading in 2032.

№15— do / don't gallerySix common errors, prevented by this guide.

DO · One italic, oxblood seal

The witnessed quarter, bound.

DON'T · Sentence-italic, gradient

The witnessed quarter, bound.

DO · Tabular hash, ledger feel

0x4f9a 2d8e c81e 7b00

DON'T · Sans, no tnum, abbrev'd

0x4f9a…7b00

DO · Sharp corners, all caps mono

Seal & download

DON'T · Pill, sentence case, sans

Seal & download ✨

№16— asset libraryWhere to find every primitive. All paths relative to brand root.

Path	Asset	Use
/assets/logo-32.svg	#32 mark · ink-on-paper	Light surfaces
/assets/logo-32-light.svg	#32 mark · paper-on-ink	Dark surfaces
/assets/logo-35.svg	#35 mark · ink-on-paper	Light surfaces
/assets/logo-35-light.svg	#35 mark · paper-on-ink	Dark surfaces
/assets/halo.svg	V silhouette · ink	Watermark, dingbat
/assets/halo-light.svg	V silhouette · paper	Watermark on dark
/assets/codex.svg	Locked-page glyph	#32 component only
/assets/dove.svg	Open-ledger silhouette	#35 component only

Colophon.

Set in Fraunces (display + body), Inter Tight (UI), IBM Plex Mono (data), and JetBrains Mono (source code). All four typefaces are free under SIL OFL or Apache 2.0. The locked palette is L1 (Paper · Ink · Oxblood) for Light surfaces and D1 (Ink · Paper · Gold) for Dark surfaces, as selected in the 250-respondent palette test. The dual-mark system uses #32 for signing surfaces and #35 for category surfaces.

TesseraSeal · Communications Style Guide · v1.0 · 2026-05-08

chain · 0x4f9a 2d8e c81e 7b00