Cutting and scoring paper

[blackarrow]

This is pretty much a rookie question, but how I can accurately cut the parts from the paper? I have a metal ruler, good scalper, but since the lines that define parts are little bit thicker, I can't assemble them very accurately at the end. It is especially visible at the long and thin parts (e.g. truck frame), where half of millimeter makes a big difference. I just started with GPM Opel Blitz 1:25.

The same question goes for scoring. The lines that define where the parts need to be scored are little bit thicker, and thus it is hard to determine the right spot to do scoring. At the end, it produces not so nice results, because the scoring is sometimes made just in the middle of the line, and sometimes at the very left or right side of it.

[airdave]

No matter what the line thickness I generally try to cut along the center of the line.

If you wish to hide the line, or try to make it disappear, you must cut on the inside of the line.
This may result in a part cut too small.

It really depends on each designer and how they create their artwork.
Some will use thicker lines than others.
Some may design parts slightly larger allowing you to cut on the inside of the line.
If you are really concerned, you'll need to contact each designer and ask for their input.

I still say, cut right on the line, at the center, as best as you can.
Then test fit the parts.
If there is excess material, you can trim the part down, removing more of the visible line.

Scoring is the same...score as closely as possible to the center of the indicated fold line.

I've never seen indicated fold lines thicker than .5mm.
That would be unnecessary
...and obvious to me, since my scoring tool is almost 1mm thick.

[Thumb Dog]

Hi All,

And hi, blackarrow. I see that you are new to the forum, and you are asking a good question concerning the basics of paper modeling. You said that you are using a metal ruler, which is what most of us use. Now, I have a question for you. Does your metal ruler have cork or other kind of non-slip strip on its reverse side?

I use a few longer rulers with cork backs, but when cutting or scoring, I always place the ruler so that its metal side is against the paper. This helps me get more accurate cuts and scores. If you cut and score while using the ruler with the cork side against the paper, the edge of the ruler is elevated above the paper, and your knife or scoring tool can wander off the line, creating parts that are too big or too small. From what I have read in the forum, many paper modelers use their cork-backed rulers in the metal-side-down manner.

Also, you mentioned you are building the GPM Opel Blitz in 1:25. That's a good looking truck. With the truck's complex frame, intricate wheels and tires, etc, you have chosen a challenging model to build. I and the other modelers here all wish you the best of luck with it, but you may want to set it aside for a time while you build up your skill level by building a few smaller and quicker models. Many free models are available on the internet, and these will help you learn where to score and cut the model's parts.

Whichever way you choose to go, best of luck with your paper modeling. We here on the forum all enjoy the hobby very much, and we sometimes hear stories of people who have a frustrating experience with their early models, and they never try the hobby again. That's too bad, because paper modeling a wonderful hobby with a deep history and a promising future.

Best of luck to you.

Score and fold,

Thumb Dog

[missileer]

There is just one thing I would add to Dave's advice and this is just my personal preference. The tabs on the bottom of building, that glue to a base plate, I score on the inside of the line. I use a knife for this score and lightly drag the blade down the line to cut the surface of the paper. Then, when I bend the tab, I get a sharp edge to contact the base with no line showing. If I am using grass or concrete colored paper for the base, I like to think it gives the impression that the building extends through the base. As I said, just personal preference. If you use this method, you may have to trim the corner edges of the tabs so that they don't overlap.

[Don Boose]

All good advice. I love this kind of question, which never fails to bring out some new information and the reiteration of time-honored practices.

Thanks for asking a good question and good luck with your future paper models.

Don

[Vinalssergio155]

Greetings, there are many opinions on this topic and each modeler uses its method. It depends a lot on the model and the design. Usually I cut by the external part of the line and to fold by the center of the line, after checking how it fits If it's too big, I cut it again on the inside. The trainers usually have to be cut on the inside. But as I said, it depends a lot on the design and for me the practice will lead to the best result, if you just start you do not get frustrated if the model is not perfect, even with much experience always something happens to us, just enjoy, relax, patience and you will see that this hobby is fabulous and will make you spend pleasant moments.

[mbauer]

As you can tell, there are plenty of different build techniques. Once you choose to cut inside, or on the outside of the line, be sure to do the same with all the cuts. If cutting the center of the line, make sure to do it the same for the whole model.

A comment that was mentioned was about your metal ruler. You do need an anti-slip surface underneath the ruler.

I don't like metal rulers or even plastic rulers because they really don't support the knife blade.

I use "quilting" rulers that have some thickness (1/8") to them They guide the blade vertically as the part is being cut out.

A thin metal/plastic ruler will allow blade "wobble", meaning your cuts won't be vertical, but more likely will end up with undercut angles. This is true if you are cutting curves or if you need to re-position the work during an elaborate cut.

Another thing you might try:

Don't just use a hobby knife and ruler. For long straight cuts try a quilters rotary cutter, for curves a sharp pair of scissors.

I have different types of blades/tools that I use for cutting. The hobby knife works great for inside work where scissors or the rotary cutter won't work.

For scoring, once again you will need to learn the technique that works best for you. Artist embossing tools are great. Many here use ball point ink pens that have run out of ink. Soaking in rubbing alcohol to remove any of the remaining ink that can destroy the design graphics.

In the past have used a kitchen butter knife back edge to score with, sewing seam thread cutter tool, pointed bamboo skewers, and even a pizza cutter.

My favorite tool is an embosser. Has a great foam grip, and is very comfortable to use.

Finishing a paper model is not like any other model media. Paper models need "creating", this is a different skill set than gluing plastic together.

You first must cut the part, then shape it to the final shape.

Sometimes you might have to assemble several pieces together to make just one part. After having assembled it, now you will probably find that a flat part just won't work.

To get it ready for attaching to the other parts, a step called pre-forming happens. Scoring the fold lines help, however you might end up rolling, bending and trimming the part to fit other parts that require the same procedures.

Engineers have tables to show them what happens when you bend a flat piece of metal. Bend Radius changes the length of the part. Same thing happens with paper. That is why some designers specify what GSM weight of paper to use.

Learning your techniques to use is part of the addiction of paper modeling. There is no secret technique that everyone can use, you must be patient and try different things when something doesn't work quite right.

Mike

[Kevin WS]

Here are a couple of basic suggestions.

1. Sounds like you are using a steel rule. Get some masking tape and stick it on the one side. This side goes on the paper when you cut or score. The tape stops it slipping. I have done this for years, I am still using the original tape!

2. Scoring. "Blunt" an old Xacto/knife blade and simply use this in another knife handle.

3. The marks used for folding or scoring. Yes, these often show. Others have given you great advice here, but if the line is on an edge and showing (like the corner of a building) then use a crayon on the edge to "colour" over. It will then look OK.

But the main thing is not to worry too much.

Just get cracking, use the tools you have to hand, think about it and you will soon develop you own way of doing things.

[MichaelS]

All these are good ideas but I really think (after only doing card models for 4 months mind you) the best thing you can do is just get in there and screw up a few and then learn from that. Build a few of Dave's Koolwheelz and try to do the best you can. The sense of accomplishment you get with doing better each time is so very rewarding.

[pjabraham]

Blackarrow,
Welcome to the forum. Consider scanning the entire model. That way you can print exact copies if you mess up. Then, if you're not sure about where to place a cut, you can simply print a copy and fool around on that without jeopardizing the original.
Phil