Common paper and film thicknesses please

[swmcl]

I'm trying to get a feel for how thick papers and films can be. I suspect there must be some specialty papers that are a huge thickness - perhaps they aren't that much thicker ...

I dunno.

So.

I would also think the films are all going to be of a similar weighting but maybe I'm wrong.

Just sheet films and enlarger papers please. Just a thing called metric sizes if possible...

Here's a start:
Sheet film - Ilford FP4+ HP5 and Delta 100 are 0.18mm

Cheers,
Steve

[Jac@stafford.net]

Just wondering why the thickness matters. Explain?

[swmcl]

Coz I'm inventin' ... The details of my product to the photographic community will be released at a later date !!

I am serious about needing to know a range of sizes.

[Drew Wiley]

Its measured in mils. Most sheets films are 7 to 10 mils thick, a few are thinner like Ortho Litho. Roll film is quite a bit thinner. Something like FP4 or TMax sheets would be representative of the most common thickness. But paper is an entirely different subject, since it doesn't have to fit in specified holder slots. You've got various thicknesses of color paper and of black and white paper, all of them fairly common. You've got RC, polyester-based color "papers" analogous to film but around 20 mils, and various fiber-based options including single-weight, double-weight, and even thicker "art" papers, all of which are classified as such according to the manufacturer's marketing policy, and not necessarily any industry convention. So as far as "inventin" - if film is involved, you have to standardize somewhere. For instance, too generous a slot in a conventional film holder, and the film risks sagging; too tight, and some films might not slide in. Gosh knows the hell I went through getting Quickload and Readyload holders to hold film consistently flat without binding during insertion. I eventually made my own sleeve holder.

[Vaughn]

Litho film runs at 0.004"

[Drew Wiley]

Somebody in that part of the world must sell a Mitutoyo thickness meter. But even a high quality micrometer or caliper would work - meaning something of machinist's quality, not a cheap knockoff. I find my Mitutoyo digital caliper "dern bloody good" to have on hand for various "inventin" tasks.

[John Kasaian]

Printing papers are generally single weight and double weight, double weight being thicker. I remember one double weight printing paper that was so thick wouldn't fit into the slot on my Ganz Speed-E-Z, it was a Russian paper no longer marketed here in the US, IIRC, maybe Slavich?

[Vaughn]

Kodak Elite double weight was almost like a 3x weight.

[swmcl]

So I'm guessing the papers aren't specified in terms of thickness ? Just a 'weight' ?

[Pere Casals]

So I'm guessing the papers aren't specified in terms of thickness ? Just a 'weight' ?

Not only photopapers, also regular paper is specified in weight per surface. Regular paper can have more or less air inside, so telling the weight/surface it tells the amount of raw material used per surface, which is valued.

[Tin Can]

Processed and very dry Ilford Multigrade Art 300 Paper is 0.018" as just measured on pound's print from the 2018/2019 Print Exchange.

Used a Starrett Dial Caliper, the same one I have used for 30 years.

The new Chinese Digital Caliper agrees, both are stored in OE cases right below this keyboard.

[Drew Wiley]

The difference is that every single Starrett caliper was individually checked and certified, which might not be the case with cheaper Chinese items - I'm certain it's not in some instances - I've heard horror stories from local machinists. Incidentally, Starrett digital calipers are now made in China, as well a particular series of extra-long calipers. They are, however, double-checked. Their classic dial calipers are still made in the US, and are of conspicuously better quality than their current digital caliper, which is understandably intended to be cheaper, since this is the more popular option of readout. That's why I opted for a relatively expensive Mitutoyo digital caliper instead of a Starrett, even though I was a Starrett dealer at that time. Paper, of course, does not maintain an absolutely consistent thickness, being somewhat hydroscopic and susceptible to changes in humidity, with thick textured "art" papers being affected the most.

[swmcl]

Thanks all but especially Randy for his measurements at this time.

If getting a range of measurements is going to be very difficult, how 'bout user's observations ?

0.018" is 457 microns or 0.457mm I think. This is substantially thicker than sheet film (~3x). Are all papers this sort of thickness and more ? Are there any that are nearer film thickness ?

[Tin Can]

I will measure more paper in the morning.

I only gave you the thickest paper I use.

[Tin Can]

I used a Mitutoyo Digital micrometer with printer (https://ecatalog.mitutoyo.com/DP-1VR-Series-264-Digimatic-Mini-Processor-C1371.aspx) for a long time, measuring paper, steel, plastics and organic thin materials. Personally producing at least a million data points, our team did billions.

Everything was outside calibrated at least once a year.

There are heavier/thicker papers than my example. Ilford is the major player in photo paper. Link is here (https://www.ilfordphoto.com/pick-the-perfect-paper/?___store=ilford_brochure&___from_store=ilford_brochure) to their papers and scroll down to a download with all products specs, except actual thickness.

We have talked about paper weight which may be related to thickness, but not always exactly. Paper density is a factor and moisture.

Single, double and triple weight enlarging paper exists. I just don't use anything heavier than double weight.

Then there are handmade papers coated with DIY emulsions that could be very thin and very thick. Some are also making DIY emulsions on film, glass, metal, wood, ad nauseam.

I recently made Ilford RC paper negs, it's coated with plastic both sides, and thin. It barely fit in my Riteway Plastic 4X5 film holders, because it was almost too thick.

Ilford MGIV RC Deluxe is 0.009" and I know you want metric, my dial calber is not and that's the way we think here. Anybody can convert to metric. And I do all the time.

I find the fahrenheit temp scale more human sensitive than celsius. I foot is almost 1 foot...I gave up on Cubits (https://en.wikipedia.org/wiki/Cubit)...:)

[Drew Wiley]

Alas Randy... Don't take me back to High School, when there was a half-hearted attempt to introduce the metric system. Shop teacher: "How many millimeter in a centimeter; hint - how many pennies in a dime?" Student: "Duuh, twelve?" Teacher: "Count your fingers, dummy!" Student: "One two three fur, .... ten, eleben, twelve". Sure enough, six fingers on each hand. Inbred. Too bad Napoleon didn't win at the end, and impose the metric system everywhere. My Mitutoyo caliper goes back and forth between metric and decimel inches at the push of a button. All my shop and darkroom tape rules have both metric and inch scales. I have interchangeable metric versus inch blades for my Starrett squares, and a special calculator that instantly converts inch fractions to either metric or decimel inches. I'm not going to replace all my beautifully machined stainless drafting rulers and T-squares that I use for print framing just because they have inch increments. It's hard to find that kind of quality anymore, let alone afford it. Many of my darkroom cylinders and beakers have not only milliliter and US fluid ounce markings, but annoying British fluid ounce increments too. No wonder they can never agree on anything. Who was Mr. Whitworth anyway? There are three different ancient definitions of a cubit, all of them more reasonable than the British one, which was seemingly based on how far a drunken Celtic priest could stagger before throwing the head of an ox.

[Jac@stafford.net]

Alas Randy... Don't take me back to High School

Have you ever left high school?

[Drew Wiley]

I must have. Even my cabinet shop is largely set up metric.

[jose angel]

Just wondering why the thickness matters. Explain?
You hit my sore. I hate this current absurdingly thick paper era.
IMHO, thin (old style) papers look better to my taste. Better to be mounted, less chemical absorption, better to wash, better to flatten, better for almost everything. Thick papers are mostly a waste.
Ok, thick papers are more resistant to damage, specially wet. That's all (and that is a lot, I know). Good for consumer needs, I think.
There was a time where single weight and doble weight was a choice. And in different surface textures. After that, a run to made the thickest papers. Paper is cheaper than silver. The thicker the better, despite of the amount of silver on them.
Now only thick double weight spongy papers... (but half weight in silver content, I'm afraid... ). Just a complain.
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Well, I suspect the OP is making focus plane calculations... mmm, interesting. I`d like to know about his project... :)