Interlace is a display mode on Amiga systems that doubles vertical resolution by alternating between odd and even scanlines each frame, achieving 400 lines in NTSC or 512 lines in PAL while maintaining compatibility with standard video signals. This technique, supported natively by the Denise chip, enables high-resolution productivity modes like 640×512 but produces noticeable flicker at 25-30Hz since only half the image lines are displayed at once. While essential for desktop publishing and video applications matching broadcast standards, the flickering made it unsuitable for most games, leading to the development of hardware flicker fixers that buffer and display both fields simultaneously.