Hello!
I feel like I jumping in for the discussion so I'm doing it. Whatever I write after this is not meant to offend anyone so if I accidentally did so, I apologize in advance!
Although I'm not sure if you are a writer, artist or both, I still feel that the post is lacking enough information to get the attention of the artist. Offering a collaboration is the same as offering work, be it paid or unpaid. You are asking for the artist's services so they have the right to know what kind of work they will be getting into.
If this is to be compared with an advertisement, then all the information the customer (in this case the artist) have is only that the story will be black and white, and it could last over 100 episodes (don't think that's enough to grab their attention at all. They'll probably just take a glimpse then walk away). But, what about the genre? Some artist may not be able to work well with a certain genre. Then, the art style? The length of each episode? Will the format be your generic manga style or is it going to be the scrolling webtoon style?
Also, here is the thing... I believe writers should have a sort of portfolio too like how artist do! To be very honest, I have no idea about comic making until like a week or two ago. I have always thought the novels I did should be enough for the artist to know of my work, but I was very mistaken! What artists wants to see are SCRIPTS!!
Scripts helps them figuring out the scenes and details for the panels. So, as a newbie author I am, started to study script writing for few hours before trying. And oh boy, was it hard... One paragraph of your novel that is not even 100 words could go for 2 pages!
Anyway, I'm getting derailed so going back to the portfolio. As I've said, I think writers should have at least one or two scripts on their portfolio if they plan to get an artist to collaborate. It doesn't have to be an existing work or something you plan to work on! It can be just a short script of a short story just so artist can get an idea how you write the script! After all, just like how writing style differ from one author to another, so does script. At least I believe so.
I think I have shared everything that I wanted to share. Lastly, I hope you get the collaboration you ask for! Wish you the best of luck!
Sincerely,
Lin XiaoLong.