: 64MB to 128MB is usually plenty for documents; higher values require significantly more RAM.

: For text-heavy reports and documents, .7z with the LZMA2 algorithm can often shrink files to a fraction of their original size, far outperforming ZIP.

: If your report contains sensitive data, 7-Zip offers strong AES-256 encryption , which can also hide filenames within the archive. Recommended Settings for Maximum Reduction

: It treats multiple files as a single continuous block, which is highly effective if your report consists of many similar documents or revisions.

If your goal is the absolute smallest file size for a long report, use these settings in the 7-Zip "Add to Archive" dialog : : 7z. Compression level : Ultra.

: Solid (this helps if you are archiving many related documents). Does 7z compress better than zip? - Microsoft Community Hub