property Glyph: TBitmap; // 12x11 pixels optionally
The Glyph property specifies the bitmap that appears on the selected CaptionButton.
If Glyph image is not specified (bitmap is empty), then CaptionButton will show the character, specified in Sign property to show it as button image.
Use the Open dialog box that appears as an editor in the Object Inspector to choose a bitmap file (with a .BMP extension) to use on the button, or specify a bitmap image at run-time.
Usually the bitmap size does not matter, but optionally, please use bitmap images with 12x11 pixels resolution.