Pressure Sensitivity

T-Sketch fully supports pressure-sensitive input for devices where it is available — like Apple Pencil or Wacom tablets. Pressure data controls brush thickness and opacity, giving you a natural drawing experience that responds to how hard you press.

Test Your Device

Use the interactive area below to check whether your device reports pressure to the browser. Press down with your stylus and vary your pressure — the bar should move smoothly from 0% to 100%.

For a more detailed test with pressure curve presets, open T-Sketch and go to User Settings > Pressure. You can read more about it in the User Settings documentation.

Supported Devices

Pressure sensitivity works with any input device that reports pressure through the browser's Pointer Events API. Common examples include:

• Apple Pencil (all generations) on iPad
• Wacom tablets — Intuos, Cintiq, One, and other models
• Surface Pen on Windows
• Samsung S Pen
• Any other stylus or digitizer that reports pressure to the browser

Mice and trackpads do not support pressure — they always report a fixed value. A pressure-sensitive stylus or pen tablet is required to take advantage of this feature.

Configuration Notes

Pressure sensitivity works out of the box in most setups, but some combinations of hardware, operating system, and browser require extra configuration.

iPadOS with Apple Pencil

No configuration is needed. Pressure works immediately in Safari and all other browsers on iPad.

Wacom Tablets

Wacom tablets on macOS and Windows typically require the Wacom driver to be installed for the browser to receive pressure data. Download the latest driver from the Wacom website and make sure the tablet is recognized in the Wacom settings panel.

Windows Tablets and Surface

Most Windows tablets and Surface devices work without extra setup. If pressure is not detected, check that Windows Ink is enabled in your tablet driver settings.

Browser Compatibility

Chrome and Firefox on all platforms provide reliable pressure data. Safari on macOS may not forward pressure from external pen tablets — if you experience this, try Chrome, Firefox, or our native desktop app for macOS or Windows instead.

Pressure Curves

Different styluses and drawing styles feel better with different pressure mappings. T-Sketch offers five pressure curve presets that control how physical pressure translates into stroke thickness:

• Auto — detects your device and picks a suitable default
• Light — less force is needed for full thickness (good for soft-touch styluses)
• Medium — balanced curve for most styluses
• Linear — direct one-to-one mapping between pressure and thickness
• Firm — more force is required for full thickness (good for stiff nibs)

You can change the preset in User Settings > Pressure inside the application. A built-in test area there lets you draw strokes to feel how each curve affects your input before committing to a choice.

Known Issues

Safari on macOS with Wacom Tablets

Safari on macOS often does not forward pressure data from Wacom tablets to web applications. If the test above shows 0% pressure or a fixed 50% with a "Mouse" device type, try the following:

• Use our native desktop app for macOS — it does not depend on Safari's Pointer Events implementation and receives pressure data directly
• Switch to Chrome or Firefox — these browsers have more reliable support for tablet pressure on macOS
• Reinstall or update your Wacom driver — an outdated or corrupted driver can prevent pressure data from reaching the browser
• Check the Wacom settings panel and make sure your tablet is recognized and the pen is calibrated

Related

• Drawing — brush engines, brush settings, and constraint modes
• User Settings — pressure curve presets and the in-app pressure test area
• System Requirements — supported browsers, devices, and input hardware