I have right in front of me a 20+-year-old Ivar shelving unit which is in its 4th (for some shelves maybe even 5th) location and second country. It still seems

I have right in front of me a 20+-year-old Ivar shelving unit which is in its 4th (for some shelves maybe even 5th) location and second country. It still seems pretty stable, although the slides on the Ivar keyboard tray sticks before the tray is fully extended (not a problem, the exposed area gives full access to the keyboard). Looking at the wood, I suspect it's spruce or pine, with visible joins in the shelving uprights, as well as in the shelves themselves.