I remember seeing (in older movies) people coming back from a vacation or something like that and pulling big white sheets off all the furniture.
As I was spreading bedsheets over my sofas this morning (my dryer works well, but sheets swirl up in balls and don’t always get 100% dry), I wondered, “does anybody do that any more?”
And, why did they do it in the first place? It can’t just be about dust, can it?
Clear Plastic Covers for just about everything
They make cloth covers too, but I always found the clear plastic ones particularly odd.
Another site: getslipcovers.com/
I don’t think the modern slipcover idea is what I was seeing in old movies. It was clear that this was something people had done while they were away, and immediately start undoing as soon as they get home.
I think I’m specifically thinking of Gaslight, which is set in the 1880s, IIRC.
I’ve known people, in my parents’ or grandparents’ generation, who never stepped foot in their living rooms. Furniture would be covered with clear plastic, and there were plastic runners on the floor to walk on (if anyone ever did). In my own generation, I have one cousin whose house is like that. I have been to her house many times, and have been in every room except the living room. I refer to it as “the Museum.”
Pets?
We keep blankets over our sofas (unless company’s coming) because of the dog – that way, we can just wash the blankets and/or sheets every so often, rather than worrying about her getting the furniture dirty or tearing up the upholstery. (Plus, she’s got her own extra blanket at the one end of the sofa)
I do, with the furniture in our cottage.
We don’t live there all the time, but we are there a lot. In between, I cover the big pieces of furniture with old sheets. It is mostly to stop things from getting dusty. It is easier to come in after two or three weeks of being away (and in the winter, it might be as long as six weeks) and whip off the sheets and run them through the washer than it is to dust everything.
It’s dust mostly. We’re also in a rural area, so some of it is cobwebs. I think in Ye Olden Days, vermin in general might have been more of an issue. Over the years, I have found a few mouse poops on the sheets. Of course, determined varmits would chew right through an old bed sheet (what I use), but if I was using oilcloth or something more study, that could probably provide more protection. Oilcloth would also help with water – this would be smart for me, actually. When we’re not there for weeks at a time, water dripping from the roof could drip for some time before it is noticed.
Part of it is sun, too – for leather and fabric, it’s nice to give them shade.
I’ve been reading Dickens and there have been a couple of references to covered furniture in great houses. I think the implication was that these were people with several homes who might be away from one or the other for months at a time. So dust, sunlight, etc. would be an issue. It also saved the servants from having to attend to unused rooms all the time the family was gone.
Thank you for that excellent answer, delphica!
Sure it can be the dust. In the past there was more of it. I remember running across a reference to congressional funding for paving postal roads in 1920. That implies a lot of dirt roads. If there were still horses about, the dust would contain powdered manure. And without AC, you’d open the windows more. More dust gets in.
I don’t know anyone doing it today. But I also don’t know anyone who’s away from their houses regularly for significant amounts of time.
I agree with the lesser paved roads. If you had any idea how much dust accumulates in a home in India…well presumably my parents were just used to it, and then I came along, aka “Toofan” or “Hurricane”, so they put regularly covers on the couch to protect them from me.
Excellent points all. The notion of “more dust back then” also kind of occurred to me when I mentioned that I thought the movie I best remembered seeing this in was Gaslight. If I remember correctly, gas lighting generated quite a bit of soot compared to modern methods.
And even as I type this response, I realize that I changed my HVAC filter this morning, and I think, “I bet a lot of houses didn’t have anything like that going for them in the 1880s.” 
They were mothballing whole wings, whole houses, for months or possibly years at a time - the servants wouldn’t have to dust everywhere in the East Wing every day while you were away in India or whatever. You could have a skeleton staff, in other words, and then fill the house back up when you returned.
Also, remember how they were lighting and heating those places - spring cleaning then really meant something, because your house would be filthy by the time spring came.
The invention of the vaccum cleaner has made a big change in how we deal with dust.
Just to back up what others are saying: I’ve only heard of sheets being used when an area of a house would be unused for a long period of time.
Another big source of dust was their use of fireplaces almost exclusively for heating. They used a lot of coal that had be carried through the house. Then it was burned, with soot and ash coming out of chimneys everywhere. And when you were done burning it, you had to scoop the ashes up and carry them out of the house.
When I was a kid some neighbors had clear plastic on their good furniture but we still sat on it. I heard later that this was very popular with northerners who were of Italian background which was the background of the people with the plastic.
The modern version of furniture plastic is people who won’t take the clear protective plastic off their electronics.