There are many printing and binding companies in China that offer hardcover book printing services. Here are a few options:

Shenzhen Mainland Printing Co.,Ltd is one of book printing companies located in China, which can provide a wide range of book printing services, such as childrens book printing, art book printing, magazine printing, photography book printing,  comic book printing, notebook printing and so on paper products . 

Full Color Hardcover Children Book Printing Services

1. C&C Offset Printing Co., Ltd.: C&C Offset Printing is a China-based company that specializes in book printing and binding. They offer a range of printing and binding services, including hardcover book printing, and have experience working with clients from around the world.

2. Shenzhen Huize E-Printing Co., Ltd.: Shenzhen Huize E-Printing is a professional printing company that offers a range of printing and binding services, including hardcover book printing. They have advanced equipment and experienced staff to ensure high-quality results.

3. Longyin Printing: Longyin Printing is a China-based printing and packaging company that offers hardcover book printing services. They have a range of printing and binding options, including foil stamping and embossing, to create custom hardcover books.

4. Beijing Huali Printing Co., Ltd.: Beijing Huali Printing is a professional printing company that offers a range of printing and binding services, including hardcover book printing. They use advanced printing technology and high-quality materials to ensure excellent results.

When choosing a printing and binding company in China for hardcover book printing, it's important to do your research, read reviews, and ask for samples to ensure that the company can meet your specific needs and quality standards.