Enhancements to the PDF underlay tool for MEP Fabrication 2018 products let you quickly import single and multiple-page PDF drawings as an underlay, and specify the new predefined scales for each individual page or all at the same time.
source
Enhancements to the PDF underlay tool for MEP Fabrication 2018 products let you quickly import single and multiple-page PDF drawings as an underlay, and specify the new predefined scales for each individual page or all at the same time.
source