Change the text in any file

Scans carry their own character: paper that is never pure white, print that has spread slightly into the fibre, and often a faint skew from the scanner bed. A correction that ignores any of those reads as a sticker.

Certificates are usually set in script or high-contrast serif faces where every letter has a distinct thick and thin. Those are the hardest shapes to approximate, which is why a hand-retyped name on a certificate almost always looks wrong.

The lines are the problem. A rule passing under a word has to continue at the same weight and position through the edit, and a break of even one pixel is visible because the eye follows a straight line further than it reads a letter.

Everything on an invoice lines up. Numbers sit in columns, labels share a baseline, and the eye reads the whole block at once, so a replacement that is half a pixel off its row is visible before anyone reads a word of it.

A label wraps. Letters near the edge of a bottle or box are compressed by perspective and lit differently from those in the middle, so replacement text that is evenly spaced across the whole word immediately looks pasted on.

Decks are built on brand colour and generous spacing, so a correction lands against a flat field with nothing to hide behind. There is no grain or texture to absorb a slightly wrong shade.

Social graphics are compressed hard by the platform and usually set in a heavy display weight over a photograph or gradient. The compression has already softened the original letters, so a crisp replacement stands out as much as a blurry one.

Meme text carries a black outline around white letters, and that outline has usually been through several rounds of re-compression. Matching the letters without matching the degraded outline is what makes a re-captioned meme look off.

A logo’s letters usually do not come from any typeface you could install. They have been drawn, kerned by eye and sometimes modified, so there is no font to fall back on and the match has to come from the letters in the image.

Posters are set in large display type where every flaw is magnified. At that size a mismatch of a few percent in weight or width is plainly visible, which is the opposite of small interface text where there is little detail to get wrong.

Interface text is small, which leaves very little letter detail to match, and it sits on bubbles whose colour changes between light and dark mode. Small text is the least forgiving case there is.

Signs are photographed at an angle, under sunlight that falls across them unevenly, and the camera has added grain on top. All three have to carry through the replacement or the panel reads as a flat rectangle of paint.