Metric photo paper sizes

[thomaso]

4 minutes ago, LondonSquirrel said:

See the point about folding A4 in half. You lose 0.5mm. That ratio has gone. √2 * 148.5 = 210. √2 * 148=209.3

The idea behind this ratio was not to use the ratio 1000% for a certain beauty of maths & formulas, but rather an economical aspect to use large print sheets in an efficient way without wasting paper for media of different sizes. As you noted in your initial post, it can be rounded for the resulting product, so it does not matter if it gets cut after binding to 148 or results in 148.5.

[grunnvms]

49 minutes ago, PaulEC said:

They may be "common" but they are not "standard" in the same way as iso 216 etc and U.S. sizes. As I've said, it is very easy for you to add these sizes yourself, but other people may require their own, different, list of sizes. It makes much more sense for individuals to add any other sizes they use regularly, (as I did with A0, A1 and A2) than for Affinity to add a random selection of "common" sizes for everyone.

If you're sending images to a print shop, they will usually adjust the size to fit the paper they are using, so getting the ratio right is probably more important than the size!

(Incidentally, I do usually use "A" size paper on the odd occasions that I print photos myself!)

So far I have not been able to find a formal standard for photo paper, not for U.S. sizes either. ISO 216 defines A, B, and C sizes, and there's also a U.S. standard that defines for instance Letter and Legal size paper. But no such thing for photo paper I'm afraid,

[R C-R]

1 hour ago, grunnvms said:

I really don't see why it should be difficult to have two sets of photo paper sizes, photo -  inch, and photo - metric. 

You can add whatever sizes you want.

[Alfred]

35 minutes ago, grunnvms said:

The whole idea of the A, B, C, and even D series paper is that the ratio between the sides is always the same with every sheet size.

 

33 minutes ago, LondonSquirrel said:

But it is not. See the point about folding A4 in half. You lose 0.5mm.

0.5 mm is insignificant, especially if you’re folding (and therefore stretching) the paper: you’ll get that much variation and more through changes in temperature and moisture content. As for cutting instead of folding, why do you think a bleed measurement of 3 mm or 1/8″ has been established as standard?

[thomaso]

1 hour ago, grunnvms said:

The wide range of ratios in photo paper is caused by different film formats, not the actual sizes. Photo paper can have a size of 4 x 6 inch, or 40 x 60 cm, both formats have the same ratio.

That's true, my point was rather the total number of globally existing, common formats that could be desired by users in the preset area.

I guess instead of requiring or demanding more default presets it could be more efficient for all users if …

… presets could get imported
… selected default app presets could get removed
… custom presets could get exported

as it is with colour palettes, assets, brushes (that users can share without further need of Serif development) … but not with export presets for instance (though this could be very useful when working with print services).

Unfortunately, Serif's proprietary file types for preferences ".propcol" / ".dat" make it impossible for users to just type/write a preset file themselves, – which could be enabled by Serif with an easier editable file format such as .xml.

[R C-R]

5 minutes ago, thomaso said:

That's true, my point was rather the total number of globally existing, common formats that could be desired by users in the preset area.

FWIW, Affinity does not even ship with presets for all the common  R series paper sizes long considered to be standard photo sizes in the U.S.

[David in Яuislip]

As realised by Lichtenberg in 1786 so that folding paper in half maintains the aspect ratio

[thomaso]

1 minute ago, R C-R said:

FWIW, Affinity does not even ship with presets for all the common  R series paper sizes long considered to be standard photo sizes in the U.S.

Which in my eyes is a useful limitation. Offering various presets for document creation might mislead or be seldom used. I guess especially for photo editing and image creation most people prefer to create documents in a size at least or larger then a 'currently' wanted output size, in the sake to ensure various layout and output sizes at any later time.

[R C-R]

2 hours ago, grunnvms said:

ISO 216 defines A, B, and C sizes...

And as mentioned here (among many other sources) it defines production paper size tolerances as below, so small or fractional mm variances do not matter.

Quote

 

±1.5 mm (0.06 in) for dimensions up to 150 mm (5.9 in)

±2 mm (0.08 in) for lengths in the range 150 to 600 mm (5.9 to 23.6 in)

±3 mm (0.12 in) for any dimension above 600 mm (23.6 in)

 

For related reasons, something similar is true for photo paper sizes, in that cut sheet sizes will not all be exactly uniformly sized even from the same supplier or photo printing service. Thus, international standards like ISO 1008 only specify nominal photo paper sizes to allow for this variation. So it is safe to ignore small fractional differences between inch & metric sizes. The important thing. like @thomaso alluded to, is that the paper size is large enough to include everything in the image that the user wants printed.

BTW, in V2 at least, any/all of the included paper size presets can be deleted & whatever custom ones anybody wants can be added, so it can be customized to whatever each user wants or needs, albeit requiring more work than some might like.

[grunnvms]

8 minutes ago, R C-R said:

And as mentioned here (among many other sources) it defines production paper size tolerances as below, so small or fractional mm variances do not matter.

For related reasons, something similar is true for photo paper sizes, in that cut sheet sizes will not all be exactly uniformly sized even from the same supplier or photo printing service. Thus, international standards like ISO 1008 only specify nominal photo paper sizes to allow for this variation. So it is safe to ignore small fractional differences between inch & metric sizes. The important thing. like @thomaso alluded to, is that the paper size is large enough to include everything in the image that the user wants printed.

BTW, in V2 at least, any/all of the included paper size presets can be deleted & whatever custom ones anybody wants can be added, so it can be customized to whatever each user wants or needs, albeit requiring more work than some might like.

Ah, thanks. ISO 1008 defines photo paper sizes. You can buy the standard, it's a bargain. Something like € 45 for 3 (yes, 3 !!) pages.

[R C-R]

1 minute ago, grunnvms said:

ISO 1008 defines photo paper sizes.

It defines only nominal photo paper sizes; IOW, not exact sizes.

[grunnvms]

I've added all the metric sizes and more inch sizes as well, so now I have a complete list of paper sizes.