I needed my shelf to sit a bit higher, so I designed this simple stackable standoff to add height without rebuilding anything or making permanent changes.

Each standoff adds 20 mm of height and features a nesting lip and matching recess, allowing multiple pieces to stack cleanly and stay aligned. The top cup helps locate a shelf leg or post, while the recessed bottom keeps stacked extenders centered and stable.

This part was printed in PETG, which gives a good balance of strength and durability for light furniture and shelving use. Other materials may work as well depending on your setup, loads, and print settings, but they haven’t been tested by me.

Features

• 20 mm height per standoff

• Stackable / nestable design

• Top cup to locate shelf legs or posts

• Flat base for stability

• No hardware or threads

Print notes

• Designed and tested in PETG

• Prints without supports

• Adjust walls and infill based on expected load

This was a quick, practical solution for a real need, but it’s generic enough to be useful anywhere a clean, modular height adjustment is needed.