Cardstock weight systems?

[SolarYellow]

I'm looking at card stock online, and it appears there are at least two different scales in use for the "lb" rating.

I'm seeing "110 lb" paper listed at 300 gsm (grams/square meter) and at 199 gsm.

297 gsm:
https://www.amazon.com/White-Cardstock-Heavyweight-110lb-297gsm/dp/B0C8W2L34M
199 gsm:
https://www.amazon.com/gp/product/B08DCF5B4P
Elsewhere, I'm seeing photo paper rated at 51 lb/192 gsm.
https://www.amazon.com/gp/product/B00004Z613/
or 48 lb / 179 gsm:
https://www.amazon.com/gp/product/B00006B7PY/
If grams and square meters don't change, then gsm is the figure I should be able to rely on being consistent.

When "110 lb cardstock" is discussed for cardstock rockets, is it the 300-ish gsm or the 200-ish gsm stuff? If the 200, would I then be happy/close enough buying the 192 gsm or even 179 gsm matte photo paper that should give really, really nice printing results?

I figure I'll use the 28-lb bond office paper that we normally use for color printing for body tube wraps. That says it's 105 gsm on the package. If I want to stay in the same system, that would mean "110-lb" should be in the 300+ gsm range. But that's pretty heavy for wrapping fins. Maybe I want to switch systems and go with 53 lb/200 gsm paper for wrapping the fins?

I know it's not difficult once the dots are connected, but I haven't been able to find any clear statements about what's what. 110 lb is not just 110 lb.

Also, if using photo paper, would I want "matte" or "gloss?" Since I'm spraying with clear after assembly, I'm thinking matte would be better for gluing.

 

[SolarYellow]

Okay, so I'm engineering my way into the light, a little bit. Dug up some links with reasonably useful information:

https://www.cardstock-warehouse.com/pages/cardstock-paper-basis-weight-chart
https://www.quill.com/content/index/paper-buying-guide/paper-weight/
Then took that info and turned it into a spreadsheet that allows me to back out what weight basis is being used for a given combination of lb and gsm specs. It also spits out the weight in grams for a letter-size sheet.

I also cross-posted this into the "What did you do rocket wise today?" thread and got some responses:

https://www.rocketryforum.com/threads/what-did-you-do-rocket-wise-today.48649/page-1552#post-2509894
https://www.rocketryforum.com/threads/what-did-you-do-rocket-wise-today.48649/page-1552#post-2509947
I don't know what's up with @prfesser's Wausau cardstock (there are other bases not listed in my spreadsheet because I couldn't find the basis sheet dimensions for them, so it might just be one of those), but you can see in the chart below that his two different Neenah products have the confusing weight/gsm specs they do because one is using the "index" basis and one is using the "cover" basis. @bad_idea's Neenah product is using the index basis.

I have some "cover" basis 65 lb/176 gsm card stock on hand that I got from Hobby Lobby. I'll start with that and see how I like it, and make adjustments from there.

My body tube wraps will be printed on "28 lb" bond paper, which is slightly more than half the weight of 110 lb index basis cardstock.

Interestingly, I've seen a sample of a really nice photo paper, which is rated at 51 lb on the "bond" basis system. It's almost the same weight as the 110-lb "index" basis material that seems to be the common recommendation. Might end up there in order to get the best quality color laser prints.

Thanks, Terry and Stephen for the info. I feel oriented well enough now to forge ahead.

The number one takeaway I wish the rocketry community would absorb from this adventure is that specifying the "lb" rating of cardstock is useless without including the rating basis, because the lb rating by itself is missing the denominator. One must either specify the basis system used or just use the gsm rating for one's statement about cardstock weight to convey actionable information.

 

[SolarYellow]

Cross-reference tables here: https://www.neenahpaper.com/resources/paper-101/basis-weights

Found a few more data points and updated the chart with additional basis labels.

 

[GlenP]

For example, two packages of cardstock from different companies:

 

[SolarYellow]

The 65 lb / 176 gsm is "cover."

The 67 lb / 148 gsm is "Bristol."

Sometimes, one company uses different bases for different cardstock products.

 

[prfesser]

Cross-reference tables here: https://www.neenahpaper.com/resources/paper-101/basis-weights

Found a few more data points and updated the chart with additional basis labels.

View attachment 614831

I think the last two columns---grams per square meter and grams per 8.5x11 sheet---are the most useful for the question "which paper his heaviest/thickest?" The "lb/500 sheets" column seems a little squirrelly; 500 sheets of 8.5x11 paper doesn't weigh 110 lb, or even 15 lb, unless the filler is uranium hexagoldite. . I'm not sure what that weight is actually supposed to represent.

Bottom line: use gsm or g/m² as the best unit for comparing heaviness or thickness. Even that unit could be a little questionable. For example, paper that has barium sulfate (dense) as a filler will weigh more than the same paper containing less-dense calcium carbonate filler. Still, g/m² is more objective than other units.

 

[GlenP]

One thing I have noticed with the typical Staples store brand cardstock is the 110# has a smoother printing surface and looks more photo realistic when I print with my ink jet printer. Their 67# paper has a light subtle texture to it and does not look as good, unless that is the effect you are looking for. I prefer their 110# paper for printing cardstock model rockets with a lot of fine detail artwork or very sharp text.

 

[SolarYellow]

I think the last two columns---grams per square meter and grams per 8.5x11 sheet---are the most useful for the question "which paper his heaviest/thickest?" The "lb/500 sheets" column seems a little squirrelly; 500 sheets of 8.5x11 paper doesn't weigh 110 lb, or even 15 lb, unless the filler is uranium hexagoldite. . I'm not sure what that weight is actually supposed to represent.

The “dims” column is the size in inches of the 500 sheets being weighed to get the “lbs” value. The different dimensions of the sheets in the different bases is the reason it can seem so goofy if lbs is the only thing reported.

 

[ReynoldsSlumber]

Here's a visual comparison of all of the paper pound weight basis sizes, so far as I'm aware. "Text" is the dark blue, while "tag" is the heavy outline. Dimensions in inches of course. As said above, the weight is determined by 500 sheets, i.e. 1 ream, of the given size of paper.