Props Making a victorian-esque sofa set in 1/3 [ongoing]

I've had this 1/6 scale set of chaise lounge, footstool/ottoman, and armchair for years. I originally got them for my old off topic dolls way back, and they're actually jewelry boxes, so they open at a back hinge.

Ever since I got into BJD I've been more into larger dolls, so I can't use these anymore, but I love the style.
Thus, I've decided to recreate them in 1/3 scale (for approx 60cm dolls) myself!

I won't be using the same fabric, but I'm going to try and make the shapes and construct as similar as possible, just in a much larger scale.

This meant I had to do a lot of math... Not hard math, just a lot of it.

PART 1 (of many, probably): Lounge Measurements
First I grabbed two roughly 1/6 scale dolls to check how well the jewelry chairs actually conformed to 1/6 scale. Both dolls are off topic, so I can't show them here. One was 26cm and one around 21cm. They had different proportions.

From this I found that the ottoman was perfectly 1/6 scale, the armchair was too wide and too deep, and the chaise lounge was slightly too small. Not surprising, since they weren't made to be scale props, but it meant that I had to adjust the measurements later.

I carefully took measurements of the ottoman and lounge (saving armchair for later as I'm anticipating it being a lot of work to alter the sizing). Then I increased the 1/6 scale measurements of the lounge by 10% to make it's "base measurements" more in line with the ottoman.


I wanted to be really precise, so I took as many measurements as possible. Then all I had to do was convert all of these to 1/3 scale. I could have done the math by hand but I'm lazy so I used a converter tool online.

I also took careful note of how each of the pieces was put together, as well as I could see. I was actually really surprised at how some of the pieces came together, as I hadn't really looked closely at them before. It's basically almost all cardstock of various thickness, covered in fabric and layered. Only the seat and backrest puff seem to be actually stuffed with anything.

PART 2: First Mock-up for Lounge
I didn't want to dedicate too much effort without knowing if the new measurements would work, especially since the lounge wasn't originally in scale and my 10% upscale was just me guessing. So I decided to make a mock-up of the important parts!

I used cardboard -- finally had a use for all those shipping boxes I saved!! -- and cut out and taped together the baseboard and seat section pieces, as well as a rectangle for where the arm of the chair would be. I was honestly really surprised at how stiff and sturdy it felt even just with these "cheap materials". It didn't even have as many layers as the final would!

I only needed to check the depth and length of the actual seat portion, so I only cut out what I needed to replicate one layer of the base and one layer of the seat (including arm indicator).

I put some printer paper over the seating area, both to make it easier to see and also because I'm afraid the blue tape would stain my doll

I tested the fit with my doll in an upright position and a reclining position and overall I felt that the scale was too small. I know chaise lounges can be small, but I prefer a couch style of size, where the person is noticeably smaller than the couch. Even if I was going for a small lounge seat, I think this mock-up would still be too small for that.

Furthermore, I feel the proportions ended up being strange. The arm feels way too narrow, but the seat feels way too wide, especially at the rounded end. I was surprised by this, because I used measurements directly from the original, and the original feels proportional to me. The original's seat definitely looks more narrow in comparison to my scaled up one for some reason.

I'll have to increase the measurements most likely. Unfortunately this means more math for me… I’m debating whether I should increase the size by 20% or 30%, or only increase certain things. I feel like it would be oddly wide if I increased everything, and the arm may still be too narrow.

What do you guys think?

 

This is SO helpful, thank you! I'll try measuring my doll and using that as a guideline for altering the seat's measurements.

I hope so!!

I'm wondering if maybe I should weight the back of the sofa a bit, if tipping tends to be an issue at 1/3 scale. The materials I'm planning to use are pretty lightweight, so it probably won't weigh a lot on its own.

Ohh I didn't even consider that that might be the case about the extra space for storage, but you're most likely right! In that case I should definitely make it more narrow at the least.
The bit about true scale vs doll scale is something I should have considered too.

For some reason I'm having trouble finding pictures of people actually sitting on these kinds of chairs, honestly. I found one painting (historical) where the seat was HUGE next to the person, even moreso than a normal couch I'd say. But then the other real life photos of these kinds of chairs, of the few I saw, most look really tiny. I'll probably try and go for a sweet spot that's more average.

 

New measurements!
Time to fix the measurements and make a new mock-up!

I followed some of the tips from previous replies, namely checking my doll's seated measurements and making the seat narrower.
I measured her thighs first and used that as a guide to guess two possible death depths, which I marked on the original mock-up.

Then I sat her down on it while it was placed on a box for height. At a fully pushed back seating position, 16cm seat depth seemed to be the best choice.

Incidentally, the height of the mock-up on the box was actually perfect for her seating height too, so I measured the distance from the seat to the table, which was also 16cm. This would be the total seat height, which includes all the baseboards, the seat while stuffed, and the chair legs.
I checked the added up measurements I currently had, and those were only 14cm total. I'm planning to also bevel the edges of the insert foam but I'm not 100% sure it will go well.

The foam I have is 2.7cm thick and squishes down to approx 2cm. I'd consider it a "working height" of 2.3 to 2.5 cm then, since I don't think a doll will compress the foam as much as me squishing it at max strength with my fingers would.
I adjusted my measurements to accommodate the foam, so the seat's total height from the floor becomes 16.4cm, which allows for the cushion to potentially squish as far as 16cm.

Second Attempt At Mock-up (50%-ish progress)
Next I decided that I might as well make a full mock-up of everything since I was having so many issues with scale.

I worked on the backboard main piece for a while. It was difficult to adjust the measurements and then accurately draw the shape. It was originally too short, and then too tall. I think I might make it slightly shorter still, but that's as easy as just trimming the bottom! I'm also considering raising the arm height if I do trim the bottom.
Notably, I just cut the original seat base for this instead of making a new one, so I need to redo the curved end too.

I stuck the seat base to the backboard at the height where the top of the foam would be. It's missing all of the bottom section for now, which I will make later, plus legs. For now, I raised it on some random objects/scraps.

Materials Planning Notes
For the good copy materials, I'm able to buy two types of craft foam board: 1.5 cm thickness, and 0.5 cm thickness.
I forgot to account for this in the original measurements, but this means anything using foam board needs to be in a multiple of 0.5cm.
I'm considering using thick cardstock for some parts that are thinner than 0.5cm or that have less even numbers, but I don't know where to buy it.
Everything will be cut with a scroll saw (I think that's what it's called, anyways) so the edges won't be nearly as jagged and rough as my box-cutter cardboard mess is!

As for fabric, I actually have no clue what I'm gonna use yet. I was considering floral cottons, or maybe real upholstery fabric, but that might be too thick. I'm either going to use a pale floral like the original, or a solid tone fabric with a subtle pattern.

 

Small ish update to sofa progress:

I used the cardboard mockup to make paper outlines, which I then traced onto the good copy material. I did adjust some of the shapes just a little.


I was going to cut it all with a scroll saw but for some reason the cut quality is awful and my blade also bent and fell off (?!).
I'm considering other tools to cut now, maybe fiskars shears or a small jig saw, but I don't know. Anyone else got ideas?

The material I'm using is foam core board from the craft store. I'm using the 0.5cm thick and 1.5cm thick varieties. Supposedly the top layers are paper and the inside is foam or polystrene(?).

Maybe using wood would be better with the scroll saw? The craft store does have some kind of material (can't find it on their website but seen it in person) that was called something like pressed...wood...something or other? About the same thickness as the 0.5cm foam board but some sort of wood particle compressed board intended for painting. Although I don't think their pieces were long enough for this sofa, I'd have to check.

Would appreciate tips/ideas!

 

I did try once with an old box cutter (like this type), but I think the blade must have been ancient and dull as rocks because the blade didn't even go all the way through after 3 very heavy-handed cuts to the same spot.
I'll definitely try again with new blades though, hopefully it works well enough! Thanks for the idea, I probably wouldn't have thought to try it again considering how poorly it went the first time. I had no clue about blade sharpness being so important!

 

By exacto knife, do you guys mean this type? I've used that specific style before and find that its cutting power is very weak and the stability of the blade is bad (wobbly!) but maybe it was old? I chose a box cutter over it because it had a larger cutting area and was more stable, and it looks like what I saw others cutting with, but I think in hindsight they were using craft knives, now that you mentioned there are craft knives that look similar to box cutters.

Unfortunately I don't think I can do this. The box cutter belongs to my father and it does have those grooves, but he doesn't want me to snap them off (don't know why). I'm just borrowing it.

I will probably look into those box-cutter-style craft knives and get one for myself!