Voice Description*: Compared to OG sans, Ink!sans is a very lighthearted, playful, and usually optimistic character and his voice should reflect that. I imagine he has a young, energetic-sounding voice. If I had to give an age to his voice, it'd probably be 16-18, though on the higher side pitch-wise. 

Mr. Amazing VA recently made an incredible fandub of a scene from Underverse. This can be used as a reference as well.

*Note: Like all voiceless characters, this is up to interpretation. If you have your own interpretation of the characters voice, by all means try it out!

UT OC Wiki Bio & Personality:

Personality:

Ink supports all kinds of art, like painting, literature, dance, music, etc. He is very passionate about art and likes to motivate characters and creators. He’s able to change clothes on people just by using his brush, and he loves to create the kind of outfit they like. Even though he uses art as a tool, no one really saw his drawings or paintings. He is afraid of whiteness, of the absence of presences or shapes around him, loneliness, huge empty spaces…

Ink!Sans has a tendency to get too excited about things. He happens to sometimes randomly vomit ink, mostly when he gets too emotionally shaken, whether from passion or shock. He also has a very short memory and will forget about different things - sometimes stopping mid-sentence to try and remember what he just said a few seconds before. This is why he takes notes on his scarf.

Ink does not appear as a perfectly well-behaved character. He can be inconsiderate, or even downright mocking and cruel, with his opinions, and deep down he sees other characters as fake story characters and not as creatures like him. He tends to be somewhat detached from his emotions. With him hardly having a proper social understanding, he’s blunt in his teasing and mocking just like in his ability to give support and to be kind. He’s a mischief-maker, and pranks are his guilty pleasure.

Ink approaches enemies carefully. He will never try to attack them first, but will mostly focus on trying to discover their motives and talk them through it. Although he does come off as a jerk on first impression, he does know what to analyze to understand the issue so he can brush people the right way and hopefully have them listen. Ink in general acts wittily and provocatively.

Bio:

Ink came from a conceptual AU that never got off the ground. He’s the first and only character with a true soul; yet despite his best effort to improve the AU, he never got a reaction from the inhabitants. In a fit of despair, he destroyed his own soul; accidentally causing him to stumble into the blank void. There he became an emotionless being alone in the vast space of emptiness.

Eventually, an ink brush (along with different kinds of paint) from an unknown artist fell into the blank canvas, each color imbuing him with feeling. After some time without color, though, he would revert to his emotionless self. Ink fixed this problem by filling vials with the colors that were splashed on him. It allowed him to pretend to have a soul so that he could feel. Gradually, Ink used the colors from the creators to create the doodle-sphere.

Eventually, he stumbles upon a portal that leads to the source code where all of the paints and colors goes to. It doesn't take long for him to discover their true purpose; to imprint the Creators' Emotions in the forms of Undertale Fan work (AUs, Fan arts, etc.). Seeing this he came to the conclusion that, in order for him to remain in this fulfilling emotional state, He has to encourage the creators to keep making and maintaining their own creations so that the paint keeps flowing through the doodle-sphere itself. Thus, to keep a steady supply of emotions for him to harness, he dedicates himself to being the Muse of the Undertale Creative Community, while he protects their creations from those who wish to harm them; be it vandals or any other off-scripted out!codes.