ngl since looking into like different types of pens ive come to really appreciate german school supplies. like we use fountain pen ink by default (using either fountain pens or ink-rollers because they have standardised cartridges while for instance ballpoint pens do not (they're essentially disposable similarly apparently the reason we were forced to only use specifically "royal blue" ink is because thats the only one that can be erased using those little solvent pens we had. other ink colours just get smudged by them like ya know what? good on you. i wish teachers had known enough about this to explain the reasoning behind these decisions to 11 year old me baffled at why im being yelled at for using green ink