Round checkered border in an optical or perspective pattern Opti-Check, short for Optical Checkered (or Checkers)
Opti-Check 4
black & white、black and white、border、Borders、checkered、frame、gray scale、GrayScale、GreyScale、grey scale、monochrome、monotone、optical、perspective、rectangle、round、square、Zaujímavé
黑，白、黑與白、邊界、國界、格仔、幀、灰度、灰階、灰階、灰度、單色、單調、光纖、透視、長方形、回合、廣場、有趣
資料來源：openclipart ( https://openclipart.org/ )