Windows 11 native apps like File Explorer and other shell apps use smooth design elements like rounded corners and acrylic by default. In addition to rounded corners, another important design feature of Windows 11 is material styles such as Mica, which make the background color of applications consistent with the desktop.
Mica is similar to Acrylic, but it works a little differently. As Microsoft describes it, the Windows Mica material creates a “color hierarchy” by aligning the background with the application to distinguish multiple open instances of the application, such as File Explorer, etc.
Currently, developers cannot enable this new material in their Win32 applications. However, this will soon change. Starting with version 22H2, developers can easily enable mica or acrylic flavors in the containers/windows of their traditional Win32 applications (i.e. desktop programs). This has been confirmed in a new document released by the company.
Mica lives inside the Desktop Window Manager (DWM), and a new Windows 11 variable called “DWM_SYSTEMBACKDROP_TYPE” will allow developers to specify mica or acrylic materials in their desktop applications. “The flag used to specify the window’s system-drawn background material, including behind the non-client area,” the support document reads. According to Microsoft, there are four constants for developers to choose from.
- DWMSBT_AUTO: Basic behavior, in this constant, the Desktop Window Manager (DWM) will automatically determine the background material for the system drawing of the application window.
- DWMSBT_NONE: Developers can skip mica or acrylic if they have custom designs for their application windows. For example, Spotify has its own title. When this value is set, Microsoft will not fill any system background.
- DWMSBT_MAINWINDOW: Apply the background material effect corresponding to the long-lived window.
- DWMSBT_TRANSIENTWINDOW: Apply the background material effect corresponding to the transient window.
- DWMSBT_TABBEDWINDOW: Apply background material effects corresponding to windows with tabbed title bars.
Mica is part of the Desktop Window Manager (DWM), which makes it available for a wide range of applications. In fact, there is a third-party open-source tool called “Mica for Everyone” that uses DwmSetWindowAttribute and other methods to force Mica to be enabled in all applications.
While this update sounds like good news for everyone, there’s a catch. Microsoft says this new variable is exclusive to Windows 11 22H2 (Build 22621). In other words, if a developer is targeting a previous version of the OS, they can only use the old material style.