Note the following and tables are from the documentation I have prepared for use elsewhere and is copyright - please do not copy or repost the text or tables without my permission.
Paper Conversions
I have noticed there is often a lot of confusion regarding the conversion of US paper to the metric equivalent and the other way around.
A lot of kits are purchased or obtained as downloads internationally, and the problem always is what equivalent paper to print on! If you are in a metric country, conversions from the US paper is difficult, especially as you can get varying results if you consult all the tables on the Internet. And I you are in a country with a US paper standard, I am sure there is the reverse problem.
So, here is a brief explanation of the US paper sizes and Metric paper sizes – and conversion charts which I hope will be of assistance.
Conversion Difficulties
Converting from one paper type to the other is not easy - they use two different standards for the various paper types – and these standards are not compatible.
Metric Paper Standards.
This is the easier standard to understand.
Metric paper is governed by ISO Standards – ISO 536 and 216 - that govern standard sizes and weights. The standards ensure good consistency, and the only thing modelers need to know really is that the standards ensure that paper thickness is consistent for a given grammage and size.
Metric paper weights are given in grammage – grams per square metre (g/m2 or more commonly gsm). The weights and thickness are standard for each paper size (the common metric paper size being the "A" sizes).
The paper sizes are based on one size down being half of the previous size.
Picture 1 below shows this clearly. The commonest paper size used by modelers is A4 (standard sized coper/printer paper) and sometimes A3 (used for larger scale models).
The thicker paper under the metric system eventually becomes classified as card.
US Paper Standards
US paper sizes are governed by the ANSI/ASME Y14 standard. The paper is used in the USA, Canada, Columbia, Chile, parts of Mexico, the Philippines and other countries. Letter, Legal and Legal/Tabloid are most commonly used sizes.
The weight used in the case of this paper is known as “basis” weight, and is the weight of a 500 sheet ream in pounds (lbs) in a given (raw and still uncut) basis sheet size.
And note, the basis sheet size is different for different types of paper. This is where the complications start, as the uncut basis sizes are not normally labeled, not formally standardised and have to be therefore be guessed from past practice. Furthermore different types of paper have different masses and weight for the same size! These include Bond Stock, Cover Stock, Index Stock, Newsprint Stock, Book Stock etc.
Doing Decent Conversions
Confused now? Never mind, logically as paper modelers we are concerned (or should be) about the paper thickness. When we build models this is what counts – too thick or thin and the parts will not fit, or will not bend correctly, or will buckle under stress and so on.
Logically as thickness is the important factor if we know the thickness of American paper or card we can use the corresponding Metric thickness. And the other way around. That way we can then do a decent conversion fit for modeling purposes.
So, in the two Tables below I have provided the various common equivalents based primarily on the thickness of the paper. The comparisons and figures are correct in terms of the thicknesses – I have checked these on actual paper in most cases with a digital micrometer.
Note the following.....
a) There is always a slight variation in the thickness of the paper. This is acceptable. Manufacturing tolerances can be up to 5-6% variance +/- on a caliper/micrometer measure. Bear this in mind if you are measuring paper as a check.
b) In terms of equivalents, I have gone for the closest equivalent in terms of appropriate thickness.
c) I have provided the paper thickness’s in the Table – if you are lucky enough to have calipers or a micrometer you can use these to reassure yourself that the actual paper you are going to use has a thickness that is OK.
d) I have also indicated the type of US Paper Stock for clarity. For modeling, we would only really use Bond Stock and Cover Stock – and these merge into each other. Cover Stock is basically card. Other types of US Stock I have disregarded completely as they would not be used for normal paper modeling.
e) For Metric paper, I have only referred to the "A" paper sizes. The other sizes would again not be used for everyday modeling.
f) The smaller and larger US and Metric paper sizes have been disregarded as these would be out of range for modeling purposes, and moreover are specialist papers and difficult to obtain.
Picture 2 is of the US to Metric Conversion.
Picture 3 is of the Metric to US conversion. Note in this Table I have suggested two different US paper weights for 80 gsm paper, as one or the other could be used (80 gsm paper being mid-range between the two). My suggestion is based on the scale of the model you are building, where the smaller scales will benefit from the thinner paper, and the large scales from the thicker paper.
Measuring Paper Thickness.
Nowadays you get electronic calipers or digital micrometers.
Calipers are cheaper.
Digital micrometers are pretty expensive but are far easier to use accurately and should be the preferred option. I saved quite a while so I could buy mine, and just made it! Picture 4 shows the set I use and the type recommend (with the micro adjustment knob at the right-hand end).
But at the end of the day, they are not really that essential......
----------------------------------------------------------
Lastly, I really hope the above is of use and encourages some of you to dig out those digital kits and now get them printed and built!
----------------------------------------------------------
Note the above and tables are from the documentation I have prepared for use elsewhere and is copyright - please do not copy or repost the text or tables without my permission.You are welcome to print out the tables for your own use.
Paper Conversions
I have noticed there is often a lot of confusion regarding the conversion of US paper to the metric equivalent and the other way around.
A lot of kits are purchased or obtained as downloads internationally, and the problem always is what equivalent paper to print on! If you are in a metric country, conversions from the US paper is difficult, especially as you can get varying results if you consult all the tables on the Internet. And I you are in a country with a US paper standard, I am sure there is the reverse problem.
So, here is a brief explanation of the US paper sizes and Metric paper sizes – and conversion charts which I hope will be of assistance.
Conversion Difficulties
Converting from one paper type to the other is not easy - they use two different standards for the various paper types – and these standards are not compatible.
Metric Paper Standards.
This is the easier standard to understand.
Metric paper is governed by ISO Standards – ISO 536 and 216 - that govern standard sizes and weights. The standards ensure good consistency, and the only thing modelers need to know really is that the standards ensure that paper thickness is consistent for a given grammage and size.
Metric paper weights are given in grammage – grams per square metre (g/m2 or more commonly gsm). The weights and thickness are standard for each paper size (the common metric paper size being the "A" sizes).
The paper sizes are based on one size down being half of the previous size.
Picture 1 below shows this clearly. The commonest paper size used by modelers is A4 (standard sized coper/printer paper) and sometimes A3 (used for larger scale models).
The thicker paper under the metric system eventually becomes classified as card.
US Paper Standards
US paper sizes are governed by the ANSI/ASME Y14 standard. The paper is used in the USA, Canada, Columbia, Chile, parts of Mexico, the Philippines and other countries. Letter, Legal and Legal/Tabloid are most commonly used sizes.
The weight used in the case of this paper is known as “basis” weight, and is the weight of a 500 sheet ream in pounds (lbs) in a given (raw and still uncut) basis sheet size.
And note, the basis sheet size is different for different types of paper. This is where the complications start, as the uncut basis sizes are not normally labeled, not formally standardised and have to be therefore be guessed from past practice. Furthermore different types of paper have different masses and weight for the same size! These include Bond Stock, Cover Stock, Index Stock, Newsprint Stock, Book Stock etc.
Doing Decent Conversions
Confused now? Never mind, logically as paper modelers we are concerned (or should be) about the paper thickness. When we build models this is what counts – too thick or thin and the parts will not fit, or will not bend correctly, or will buckle under stress and so on.
Logically as thickness is the important factor if we know the thickness of American paper or card we can use the corresponding Metric thickness. And the other way around. That way we can then do a decent conversion fit for modeling purposes.
So, in the two Tables below I have provided the various common equivalents based primarily on the thickness of the paper. The comparisons and figures are correct in terms of the thicknesses – I have checked these on actual paper in most cases with a digital micrometer.
Note the following.....
a) There is always a slight variation in the thickness of the paper. This is acceptable. Manufacturing tolerances can be up to 5-6% variance +/- on a caliper/micrometer measure. Bear this in mind if you are measuring paper as a check.
b) In terms of equivalents, I have gone for the closest equivalent in terms of appropriate thickness.
c) I have provided the paper thickness’s in the Table – if you are lucky enough to have calipers or a micrometer you can use these to reassure yourself that the actual paper you are going to use has a thickness that is OK.
d) I have also indicated the type of US Paper Stock for clarity. For modeling, we would only really use Bond Stock and Cover Stock – and these merge into each other. Cover Stock is basically card. Other types of US Stock I have disregarded completely as they would not be used for normal paper modeling.
e) For Metric paper, I have only referred to the "A" paper sizes. The other sizes would again not be used for everyday modeling.
f) The smaller and larger US and Metric paper sizes have been disregarded as these would be out of range for modeling purposes, and moreover are specialist papers and difficult to obtain.
Picture 2 is of the US to Metric Conversion.
Picture 3 is of the Metric to US conversion. Note in this Table I have suggested two different US paper weights for 80 gsm paper, as one or the other could be used (80 gsm paper being mid-range between the two). My suggestion is based on the scale of the model you are building, where the smaller scales will benefit from the thinner paper, and the large scales from the thicker paper.
Measuring Paper Thickness.
Nowadays you get electronic calipers or digital micrometers.
Calipers are cheaper.
Digital micrometers are pretty expensive but are far easier to use accurately and should be the preferred option. I saved quite a while so I could buy mine, and just made it! Picture 4 shows the set I use and the type recommend (with the micro adjustment knob at the right-hand end).
But at the end of the day, they are not really that essential......
----------------------------------------------------------
Lastly, I really hope the above is of use and encourages some of you to dig out those digital kits and now get them printed and built!
----------------------------------------------------------
Note the above and tables are from the documentation I have prepared for use elsewhere and is copyright - please do not copy or repost the text or tables without my permission.You are welcome to print out the tables for your own use.
Aucun commentaire:
Enregistrer un commentaire