Some languages (Japanese, Chinese, etc.) are not supported by the default font included with the plugin, in this case a custom font is required.

1.
First, copy all the files in wp-content/plugins/woocommerce-pdf-invoices-packing-slips/templates/Simple/ to the following path in the (sub)topic:

wp-content/themes/my-(child)theme-folder/woocommerce/pdf/my-template/

Name the parts in bold in the path. Normally I will name it as cn-template, the Child Theme folder is depend on what Theme we use, normally we only use Flatsome, so the file path should be : wp-content/themes/flatsome-child/woocommerce/pdf/cn-template

 

2.
Then create a folder fonts/, and upload the Chinese font of your choice to it. Note that only TTF font files are supported here. If you are looking of CN Word file ttf, you can try the link provided in below one.fanti/繁体:https://drive.google.com/file/d/1MEXSVdd1FGM5pdM1ZKMYRnx9idzUBA1k/view?usp=sharing

jianti/简体:

https://drive.google.com/file/d/15XwPFw4VtNd0z02VTwRqmGqGAE7aRwfn/view?usp=sharing

3.
Open the style.css file in my-template and add the following styles:

@font-face {

 

font-family: ‘MyFont’;

 

font-style: normal;

 

font-weight: normal;

 

src: url(<?php echo $this->get_template_path(); ?>/fonts/FangZhengHeiTiJianTi-1.ttf) format(‘truetype’);

 

}

 

 

@font-face {

 

font-family: ‘MyFont’;

 

font-style: normal;

 

font-weight: bold;

 

src: url(<?php echo $this->get_template_path(); ?>/fonts/FangZhengHeiTiJianTi-1.ttf) format(‘truetype’);

 

}

 

you can add more style like Italic or Strike line but normally we no need to add cuz no much free ttf file we can use. Then, change the body Font CSS to the font-family you apply just now, like : MyFont

body 
{
 background: #fff;
 color: #000;margin: 0cm;
 font-family: 'Open Sans', sans-serif;
 font-size: 9pt;line-height: 100%; /* fixes inherit dompdf bug */
}
4.
Enter the plugin backend, select the newly created template (cn-template) in Choose a template, and the problem of Chinese display will be solved after enabling it.

Remember to check “Enable font subsetting” under General settings. When this option is activated, only the characters actually used will be embedded in the PDF file instead of the entire font. This approach can effectively reduce the size of the generated file.

Small Tips:
1. If you know about html and wanna know what is happen, like for example you want to change the color but no effect, you can add &output=html at the back of pdf invoice URL like

https://mediaplusdemo.com/jtest/wp-admin/admin-ajax.php?action=
generate_wpo_wcpdf&document_type=invoice&order_ids=3536&_wpnonce=e10b93d3d8
https://mediaplusdemo.com/jtest/wp-admin/admin-ajax.php?action=
generate_wpo_wcpdf&document_type=invoice&order_ids=3536&_wpnonce=e10b93d3d8&output=html