I keep the box top, not the whole box. 130 box tops stacked one upon another is about 6" high and the size of the biggest box top.
unless you are planning to frame them, or you actually look at them at least once a year. Throw them out. Watch an episode of ‘Hoarding’, that’s enough incentive for me to clean house. 
I keep a few around, but only to store unused parts and decals from various kits.
Straight into the trash when done!
I ceased buying modeling magazines due to the amount of space 30 years worth consumed.
A once in a century flood destroyed the magazines I had accumulated and I have been very reticent about buying more.
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Those boxes I retain for their artwork are few and primarily saved due to nostalgia reasons.
If a fire hazard exists, I would be more concerned about a collection of petroleum based plastic kits in both assembled and unassembled form as well as the wood book cases containing the kits.
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I do collect photos of kit boxes on my computer instead of storing the boxes.
Photo viewer software will display the photos in whatever order I wish while I work at my bench.
Like many others here, I keep teh instructions and toss the box. With a stash of around 400 kits still to go, I have no room for empty boxes. A few of the empties do get dragooned for storage purposes of excess items that for one reason or another can not go into my spares storage bins. But otherwise, I get rid of the box upon completion of the kit. In spite of some very nice box art. Unlike my boyhood building days.
I keep the instructions, keep any spare decals, use the box bottoms for airbrush practice and then toss them! As for the tops…I have been keeping them. [:$] Mostly for the box art. I do flatten them and store them, but that to does start to add up. But for now I keep the tops. Very interesting to see the comments here. I like the idea of taking pics of the tops. And I may get to the point where I get rid of them. I have heard of some people using them to decorate their hobby area.
Eagle90
I also pitch box but keep instructions
Don Stauffer in Minnesota
- Taking that a step further Don, do you have a filing system or specific way you catalog them? or are they just stashed in a box?
I was just thinking about this recently, as the number of completed builds goes up, there may come a day when you want to reference something from one of them.
Hi :
I rarely keep the boxes . If the box art is something special the box top and instructions go in a manila envelope , clearly marked in a hanging file " fire-resistant " cabinet .
I do the same with my LEGO collection .That way I can actually see what I have . Now for the workbench I have little and not so little file boxes on the back edge and on a shelf unit filled to the brim with aircraft parts in specific color files .
Cars in grey ones ,Ships in blue ones and planes in white ones .Figures and miscellanous go in brown ones .Train related and scratch -parts go in black ones . Train stuff has to be included for two reasons .I am the Vice - President - Modeling at the Museum where I volunteer and I use a lot on my scratch-built ships too .
I don’t keep a lot of boxes around , specifically because of fire hazard .There’s nothing to be done about the models though . I have never seen models survive a fire anyway . Even in special cases , the heat is the destroyer there .
I keep the boxes…with leftovers and the instructions inside. But reading this thread has given me thoughts. I think I’ll come up with a “leftovers” box, a folder for the instructions, and get cheap frames for the front covers.
I keep just the box top; I have them all stuck up around my shop area. I also file the instructions.
But I happily throw away the remainder. The size of my model hoard is a little embarrassing, and I need to clear out!