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

Outlined Line - Streamline Material Free

Arrow Insert

UI Actions

Rounded Line - Streamline Material Free

Sharp Fill - Streamline Material Free

Arrow Top Left Fill

Arrow Back 2

Ultimate Duotone - Free

Arrow Right

Arrows Diagrams

Flex Gradient - Free

Download Arrow

Core Flat - Free

Arrow Up 1

Ultimate Bold - Free

Sharp Line - Streamline Material Free

Guidance – Free

Up Arrow

Core Flat

Triangle Arrow Left 1

Single Triangle Arrow

Core Duo

Line Arrow Left 1

Single Line Arrow

Core Solid

Sharp Line - Streamline Material

Arrow Downward

Outlined Line - Streamline Material

Rounded Line - Streamline Material

Big Arrow Right

Line Start Arrow Notch

Text Formatting

Nova Line

Refresh Arrow 2

Synchronize

Arrow Outward

Arrow Upward

Arrow Forward

Cyber Line

Arrow UP

Keyboard

Arrow Split

Outlined Fill - Streamline Material

Line Start Arrow Notch Fill

Ultimate Duotone

Arrow Left

Ultimate Bold

Arrow Left 2

Ultimate Regular

Cyber Duotone

Arrow Down

Ultimate Colors

Platinum

Right Arrow

Basic Arrows

Plump Pop

Arrow Vertical

Plump Duo

Core Remix

Arrow Back

Freehand Duotone

Left Arrow

Arrow Right 2

Arrow Up 2

Arrow Next

Arrow Up

Arrow Shift

Arrow Down 2

<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

---

## 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

---

## Brand & Cultural Identity

### What it communicates

> "We illustrate nature's geometry."

---

## 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.

---

## 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

Line Arrow Up 1

Line Arrow Up 1 icon - Flex Flat Set

Download Line Arrow Up 1 SVG vector or transparent PNG icon in Flat style(s) for Sketch and Figma. It belongs to Flex Flat vectors SVG collection.