Interface Essential

Technology

Artificial Intelligence

Computers Devices Electronics

Programing Apps Websites

Internet Networks Servers

Business Products

Work Office Companies

Money Payments Finance

Shopping Ecommerce

Shipping Delivery

Typeface

Content

Design

Images Photography

Music Audio

Video Movies TV

Files Folders

Users

Avatars

Emails

Phones Mobile Devices

Messages Chat Smileys

Social Medias Rewards Rating

Travel

Hotels Spas

Wayfinding

Food Drinks

Furnitures Decoration

Lamps Lights Fire

Clothes Footwear Accessories

Tools Constructions

Ecology

Nature Farming

Pets Animals

Weather

Health Beauty

School Learning

Science

Culture Religion

Romance

Family Babies Kids

Holidays

Sports

Outdoors Recreation

Entertainment Events Hobbies

Video Games

Crime War Protection

Transportation

Maps Navigation

Building Construction

Landmarks

Real Estate

Arrows Diagrams

Logos

Cannabis

Streamline 3.0

Ultimate

Core

Flex

Sharp

Plump

Micro

Freehand

Streamline Material

Nova

Cyber

Streamline Vault

Pixel

Google Material

Tabler

Remix

Feather

Iconoir

Carbon

Solar

Lucide

Brand Logos

Bootstrap

Atlas

Unicons

Ionic Icons

Phosphor

MingCute

Font Awesome

Majesticons

Mynaui

Radix

Heroicons

Flagpack

Typeface - Free

Letters

Ultimate Light

Ultimate Bold

Ultimate Regular

Sharp Line - Streamline Material

Social

Rounded Line - Streamline Material

Outlined Line - Streamline Material

Power Outlet Type O

Power Supply

Opera Logo

Browser

Rounded Fill - Streamline Material

O2 Fill

Sharp Fill - Streamline Material

Outlined Fill - Streamline Material

Ultimate Colors

Pollution O2

Pollution

Ultimate Duotone

Freehand Duotone

Pollution O 2

Flex Duo

Number Zero Square

Mathematics

Core Duo

Number Zero Circle

Core Solid

Core Neon

Core Remix

Core Gradient

Core Pop

Kai OS Logo

OS Systems

Font Awesome Solid

solid3

Oxygen Tank O2 1

Medical Instruments

Oxygen Tank O2 2

Pollution O2 Message

Pollution O 2 Message

Blood Drop Type O

Blood

<p>Bold style features strong, solid shapes for instant recognition. It gives excellent legibility on dark backgrounds.</p>

**Summary**: Solid opaque fills with transparent cutouts and rounded outer silhouettes, monochrome — the highest-weight Ultimate sub-style. Notably harder and more serious than its line-weight siblings despite sharing the same rounded geometry. The tone signals confidence and directness: solid visual weight that reads as active, selected, or primary without requiring colour. Best for active states, mobile tab bars, badges, dark-mode-first products, and any context requiring maximum legibility at 12–16px; best used as the emphasis layer alongside Regular rather than as the sole icon weight.

**Last updated**: 2026-04-23

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## Fit & Recommendation

### Primary use cases

- Feature callouts and hero icon moments
- Navigation tab bars on mobile
- Badge and status indicators
- Dark-mode-first products
- Any context requiring maximum legibility at very small sizes (12–16px)
- Promotional materials and app store graphics

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## Brand & Cultural Identity

### What it communicates

> "We are confident and direct."

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## Visual & Technical Specs

### Visual properties

| Property | Value |
|----------|-------|
| Stroke weight | None (solid shapes) |
| Fill | Opaque fill with transparent cutouts |
| Corner treatment | Rounded outer silhouettes |
| Color | Monochrome |

### Emotional Scores

Ultimate Bold is near neutral on warmth leaning slightly cold — solid black fills are high-contrast and authoritative; not cold, but not warm. It is among the hardest sub-styles in the catalog — solid shapes represent the highest visual weight in the family and are unmistakably hard. It is somewhat formal — heavy fills read as authoritative and direct, with rounded silhouettes preventing full formality. It is one of the more serious sub-styles in the catalog — strong graphic weight signals seriousness with no decorative elements. On its human↔mechanical character, it is somewhat mechanical — rounded outer shapes retain some human quality while the density of fill reads as systematic.

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## Pairing & Compatibility

### Typography pairing

- **Primary**: Archivo Black / Space Grotesk Bold — matches the visual weight of solid icons
- **Display**: Syne, Clash Display — adds graphic boldness in marketing contexts
- **Body**: Inter Regular — provides contrast between the heavy icon and light body text
- **Avoid**: Ultra-thin or hairline fonts — the visual weight imbalance is extreme and reads as unresolved


<p>The world's largest icon family with encyclopedic coverage. Designed over twelve years, Ultimate offers every concept from common to rare icons. It's a neutral style and fits most use cases.&nbsp;</p>

The encyclopedia of icons

O icon - Ultimate Bold Set

Download O SVG vector or transparent PNG icon in Solid, Filled, Bold, Glyph style(s) for Sketch and Figma. It belongs to Ultimate Bold vectors SVG collection.