Use original PDF not a flattened copy of the PDF
Risk
PDF with flattened layers reduces the usability of a PDF.
Issues
PDF with flattened layers that makes it much harder to extract contents.
Example
Solution
Dos:
Create PDF with layers.
Keep all text live, for accessibility.
Standirise on layers (Dielines, Artwork, Braille, Barcodes...).
Don’ts:
Flattening layers.
Use pdf.
Tips
The following steps describe how to view information about how to create PDF with layers:
InDesign and Illustrator,
Export to PDF → Choose the PDF Preset → Make Sure to Check the (Create Acrobat Layers Top-Level Layers).
The layers compatibility is up to Acrobat 6 (PDF 1.5)