Interface Essential

Business

Images Photography

Money Shopping

Programming

Computer Devices

Phone

Mail

Map Travel

Food Drink

Nature Ecology

Entertainment

Shipping

Culture

Health

Work Education

Artificial Intelligence

Arrows

Streamline 3.0

Ultimate

Core

Flex

Sharp

Plump

Micro

Freehand

Streamline Material

Nova

Cyber

Streamline Vault

Logos

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

Cyber Duotone - Free

Email 2

Mail Chat Smiley

Cyber Line - Free

Cyber Line

Email 1

Emails

Cyber Duotone

iOS 14

Email

iOS icons

Ultimate Bold

Read Email Laptop

Read Email

Send Email Fly

Send Email

Read Email Letter

Ultimate Regular

Send Email Monitor

Ultimate Duotone

Read Email Hand

Ultimate Bold - Free

Ultimate Colors - Free

Nova Solid

Email Read

Email Actions

Ultimate Colors

Ultimate Light

Email Action Reply All 2

Email Send 3

Email Address 1

Nova Line

Email Forward

Email Action Send

Ultimate Regular - Free

Outlined Line - Streamline Material

Stacked Email

Communication

Email Action Add

Send Email 3

Rounded Line - Streamline Material

Alternate Email

Read Email AT Alternate

Email Action Read

Freehand Duotone

Email Action Play

Read Email Circle

Email Action Clock

Email Action Star

Email Action Subtract

Ultimate Light - Free

<p>Flex is all about the curves. Its smooth curves brings fluidity and dynamism to your designs with a modern appeal.&nbsp;The Flat style is easy to integrate into projects that need icons with a more illustrative purpose, working best at larger sizes. All Flex Flat icons are designed on a 14px grid with two customizable colors.</p>

Flex Flat

**Summary**: Flex's illustrative sub-style — solid flat two-tone blue fills on fluid organic silhouettes, producing a more contemporary and natural-feeling flat illustration register than geometric flat sets. Fluid organic edges soften the flat fill quality, making this register warmer and more natural than Sharp Flat or Core Flat at equivalent blue tonal palette. The tone signals organic illustration: "we illustrate nature's geometry." Best for onboarding and product tour illustrations at display sizes, feature explainer content in modern consumer products, and marketing where organic silhouettes feel more contemporary than geometric flat alternatives.

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

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## Fit & Recommendation

### Primary use cases

- Onboarding and product tour illustrations at display sizes
- Feature explainer and help content visuals
- Modern consumer product marketing where organic silhouettes feel more contemporary than geometric flats

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## Brand & Cultural Identity

### What it communicates

> "We illustrate nature's geometry."

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## Visual & Technical Specs

### Visual properties

| Property | Value |
|----------|-------|
| Stroke weight | None |
| Fill | Solid flat fills, two-tone |
| Corner treatment | Fluid organic silhouettes |
| Color | Dark blue + light blue tonal |

### Emotional Scores

Flex Flat is somewhat warm — the blue tonal system is cool, but organic silhouettes add warmth that geometric flat sets lack. It is one of the friendlier sub-styles in the catalog — flat fills on organic silhouettes produce flowing shape edges that soften the fill. It is one of the friendlier sub-styles in the catalog — the two-tone blue in organic shapes reads as modern and considered, with mild approachability. It is somewhat warm on playfulness — organic flat illustration reads as contemporary and considered rather than playful or severe. On its human↔mechanical character, it is one of the more human-feeling sub-styles in the catalog — fluid organic silhouettes read as natural forms, not diagrams.

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## Pairing & Compatibility

### Typography pairing

- **Primary**: Outfit — modern humanist, appropriate for the illustrative flat icon context
- **Alternative**: Plus Jakarta Sans — warm humanist, works in illustrative contexts
- **Body**: Inter Regular or DM Sans
- **Avoid**: Cold geometric or monospace fonts


<p>Flex is a fluid icon family inspired by nature’s curves. It favors smooth, flowing forms. More organic than Core and subtler than the chunky Plump. Read about the <a href="https://blog.streamlinehq.com/flex/" rel="noopener noreferrer" target="_blank">design process</a>.</p>

Fluid icons

Email Attachment

Inbox

Email Attachment icon - Flex Flat Set

Download Email Attachment SVG vector or transparent PNG icon in Flat style(s) for Sketch and Figma. It belongs to Flex Flat vectors SVG collection.