PDF Filesize

There are 2 ways to reduce PDF filesize:

1. Reduce the resolution of the logo used for the header (300dpi is considered as the standard for both online and print usage) in JPG format (rather than PNG). Do note that if you change the logo, this will not automatically affect existing invoices unless you enable the option “always use most current settings” under Documents > Invoice.
2. Enable “font subsetting” in the General settings

Let us know if that helps or if you need more help with any of the above.

Thank you @pomegranate
Not the loge was the Problem – the product image on every position. i disabled that.