Quadrant Upper Left

Building small pictures out of text, one quarter at a time. Picture each character slot split into four squares. ▘ paints the top-left one and leaves the rest empty. Its siblings paint the other corners, halves and diagonals, so a row of these characters works like a row of chunky pixels.

Ten quadrant characters (▖ ▗ ▘ ▙ ▚ ▛ ▜ ▝ ▞ ▟) plus the half blocks ▀ ▄ ▌ ▐, the full block █ and an ordinary space give every one of the 16 possible on/off patterns of a 2×2 grid. That doubles the detail in each direction on a text screen, which is why programs that draw images, logos or graphs inside a terminal can use them. The set comes from the block graphics of older computer terminals, where letters' cells were the only way to draw; teletext-style mosaic screens used similar tiles.

Why do my blocks have gaps or look off?

The font and line spacing decide whether tiles touch. Block art only looks solid when the font draws each block to the very edge of its cell and lines sit with no extra spacing. In a proportional font or with loose line height, you can get stripes and gaps. Use a monospaced font (one where every character is equally wide) and tighten line spacing until the tiles meet; a font missing the character may show an empty box instead.