I think everyone has answered your question correctly so far. You can’t beat plywood for strength, but it is expensive. There are middle ground alternatives.

There is Medium Density Fibreboard (MDF) which is between the two on strength but takes paint brilliantly. Many cabinet makers use this exclusively for mid range quality furniture.

Even cheaper is chipboard which is about as bad, or worse than OSB but you can get it laminated. Most very cheap furniture from places like IKEA use it and it can do a reasonable job.

All of these materials have their quirks, mainly on how you finish end grain (even plywood). Both MDF and chipboard suck at taking a screw so you have to get special screws and use them carefully. Make sure you do some research, there’s plenty of YouTube videos on using the products.

It’s not just weight but friction. Depending on the flooring you could add a rubber pad to the bottom of the piece to help. If you do go the cavity route, steel washers are pretty cheap and would be heavy, or as someone else suggested, some lead weights will work.

Nice, how different does it sound to a modern one?

I saw a tip for paint recently that I haven’t tried yet, but it might work here too. If you get some painters tape and make a V over the top it acts as a spout and it never gets on the threads

Link to image

I loath getting on my high horse, but don’t take things from forests unless they are explicitly there for the taking or you have permission from someone. The odd small item here and there may not seem significant but if everybody did it it would have a significant impact.

I wish I had the time to do this but I look forward to the entries.

I don’t want to be preachy but I’d like to take this opportunity to draw everyone’s attention to the sustainability of rare hardwoods.

I could talk at length about the socioeconomic impact of rare hardwoods as well as the environmental impact, but to keep it short, the wood database has a good article on the sustainability of darkwoods.

https://www.wood-database.com/ebony-dark-outlook-dark-woods/

Another useful method is drilling out the hole and filling it with matchsticks and wood glue. Let it dry, cut it flat and rescrew the hole. It takes a while longer to dry but I think it might be more secure than hot glue.

I think it depends on how much you are willing to maintain it and if you are flexible on the types of materials you use. Where you live will have a significant impact as well, if you live near the sea up north then you are going to have a harder time than if you live inland in the south.

BLO works but you will have to maintain it regularly and how regularly depends on the weather.

You can use specific wood types that work well outside; pressure treated timber starts off looking a blue/green colour but fades to a silver and won’t need looking after for a long time. Teak is the classic option for outdoor furniture as it’s naturally resistant to pests and erosion, it’s an exotic hard wood though so not the most sustainable. White oak is resistant to rot as well but isn’t easily available. . Any of these with an annual coat of BLO will probably keep them looking new, if you don’t mind them becoming more rustic then you can leave it for longer.