The bottle had a shallow well in the glass at the top for the easier filling of your pen.
Ink came in different colors, and in permanent or (allegedly) washable.
The Skripsert pen was, I believe, Sheaffer's first pen filled by an ink cartridge. Oh, joy! No open bottle of ink! Nothing to spill, nothing to fill. You just take apart the pen, slide the empty ink cartridge out, and pop a new one in, with no ink anywhere near your hands or furniture. This is how virtually all modern fountain pens and technical pens are filled.
Skripsert was the name Sheaffer gave the pen that could have the Skrip inSerted into the pen via a cartridge. It was mid-century advertising ploy, cutesie brand names made of combined words.
Here is the pen.
And here is the matching pencil.
It's a smaller twist pencil at 4 & 5/8 inches. It uses the thinner 0.9 mm lead.
You can't quite see the blue eraser -- it's worn down to a nub.
For more of my family Sheaffers: