@danielerossi this is probably because 8x10 is very close to letter sized paper (8.5x11) which is the most popular standard paper size in the US. Since things like envelopes, printers, and the paper mills themselves are optimized for letter sized sheets its easier, cheaper, and creates less waste for the sketchbook companies to offer a letter sized sketchbook instead of an 8x10.

If there is a specific kind of paper you want you may have to go for the slightly larger size and cut down the sheets yourself after you're finished or you could just mark off an 8x10 box in the middle of the sheet and have your finished work be 8x10 on an 8.5x11 sheet and let the customer decide whether they would like to cut it down or frame it with a matte.

I attended a talk on illustrating early chapter books at a SCBWI conference a few weeks back, here are some of my notes. In the talk, the art director said there were two "categories" for early chapter books

• First to Second Grade These manuscripts are normally 4-5 pages of plain, typed-out, unformatted text. There are illustrations on every page of the final book layout and they should relate very closely if not exactly to what is written on the page (kids will use them as context clues). This normally results in a 60-80 page book.

• First to Fourth Grade These books can be slightly longer, around 90-120 pages and have illustrations on most but not all pages. The illustrations have a little bit more flexibility as to how closely they align with the text.

As far as genre, she was saying that almost all beginning chapter books are simple concepts, exciting, action packed, and do not try to tackle any sort of complex emotional issues. Many of them are silly or include some sort of comic relief. They are meant to help kids improve reading skills and feel excited and accomplished about reading on their own, not get them thinking about plot or theme. More complex plots or challenging themes are more appropriate for middle grade chapter books.

If you were going to try to publish the traditional route I think you'd want to write the manuscript and then shop around for a literary agent to sell it to a pub. You could mention that you are interested in illustrating and do some samples but the publishing house's design team will have a lot to say about word count per page, page count, where illustrations should go and how much space there is for them.

Another thing that I noticed was that they make almost all early chapter books into multi-book series (like magic treehouse). That may be something that you'd want to consider. Maybe you'd want to shop around a manuscript plus ideas for the next two books instead of just the one. Good luck and I hope this helps, I think that your mouse adventures could make an awesome early chapter book!

@Braden-Hallett lol so dark

I agree with @SFischer 's suggestions and would take it a step further, crop in on the subjects and simplify to a single light source (the moon) in the BG.

I use a moniker for consistency in handles and urls (and because no one can ever remember or spell my name).

I've been working on a piece for Chicago SCBWI's Prairie Writers and Illustrators day:

@Настя-Волкова Have you listened to the creative pep talk podcast at all? I think you could get a lot out of it. Andy, the host, is very open about his ADHD and how it effects his creativity. Here are two episodes that specifically call it out in the title but he talks about it often in other episodes as well.

http://www.creativepeptalk.com/episodes/2018/11/27/209-self-doubt-adhd-and-breakthrough-with-saiman-chow

http://www.creativepeptalk.com/episodes/2017/7/26/143-rogie-king-on-adhd-faith-the-power-of-combining-your-skills

@BichonBistro

@arent-draper I think the answer is yes and no. If you are aiming to do children's books some of your images should show that you can create a composition with room for text but it is fine if some of them do not. In some cases you will have a single page illustration with the text on the opposite page or a vignette with the text above or below.

I have been working on some two-page spreads for my portfolio and I find it easiest to make up some text (It doesn't have to be the most spectacular writing in the world) or to borrow some text from the public domain to mock into my competitions. When thumbnailing I know a lot of illustrators will draw in some horizontal black bars to represent the visual weight of a text block to help achieve a balanced composition.

@xin-li That's how I show my process, I do it in a blog and then have a link from the polished work to the process, that way people who want to see it can find it easily but the people who would be put off by rough sketches or a screenshot where I still need to fix a bunch of things aren't distracted by it.