Scale weight for mixing ink

This is the one I use. I use the g for all weight parts in the Pantone Book. I place the wax paper on the scale and zero it out then place the first color on the wax paper and measure and repeat the process. I then move all ink from the wax papers onto a mixing surface and mix.

x parts = x g and so on.

I’ve used this for 4 years now and it’s worked perfect.

Casey
Inky Lips Press

I used my digital postal scale recently and the results were spot on. Cost me $30, and it’s invaluable for metering my postage on retail orders as well.

It has a tare button for zeroing out a container or plate for your individual inks, and will measure down to 1/10th of an ounce. I usually follow the pantone formula and mix an ounce of ink for small jobs to avoid waste.

James Beard
Vrooooom Press
www.vrooooom.org

I believe the 99% of the customers won’t notice any difference if you used a common food scale or better :)

There are some “pocket scale” on eBay, very cheap that you can use for a max of 250gr of ink.

Fabio

Thanks, everybody, for giving advices about scale for mixing inks.

The best way I have found to do it is to weigh your can of ink (X), then Tare the scale back to zero, remove the ink you wish to add to your “Pile” with color 1, weigh the can again (Y), establish how much you removed as the difference (it should be X-Y=Z) and then measure that against the other colors.

A 1 LB can of ink on a scale that has greater capacity than 1 LB (for example, a 5 LB scale) should be accurate, and REMOVING ink from the can until the desired amount is reached will be easier than trying to put ink on a piece of glass on a scale. You can be more precise this way and add ink directly to your pile, straight from the knife.

If you use this method, all you really need is a scale that is about 5X the amount of your heaviest can of ink. So, if you pull from 5LB cans, you should get a 25 LB scale. You just want one that will be sensitive enough to read a couple decimal places in case you’re mixing small quantities.

I’ve always mixed ink additively (adding it to the mixing board which is tared out on the scale). The old triple beam Ohaus scales (good for up to about three pounds) work great, though you have to remember the additive amounts of each color. Also adding very small portions is not a problem if you tip the ink on/off with the corner or the knife. If you’re mixing from the newer Pantone books which give formulas as percentage, mixing in grams on the newer electronic scales is a breeze.

Still for all that, you have to adjust the color with mixing white to get the printed color to be the same as the book color—there is a major difference in intensity between ink mixed for offset vs letterpress.

I just use pieces of used tympan paper cut to 5.5 square; the triple beam balance is quickly zeroed for that. I measure each ink separately onto the paper and then scrape them onto the slab. If it is a large mix and I need an amount than can’t be contained in that area, I split the amount into two and add them on the ink slab.
For small runs I just mix 100 grams (unless it is a simple formula like 50-50) and the triple beam balance is quite accurate for that, as would most digital scales.
Some are satisfied with volume or visual mixing methods, but weight is the only way to mix if your customers want metallic mixes (which are more dense than regular PMS inks), and weight is the actual basis of the PMS system.

Sounds reasonable as well- but creates waste in the form of 5X5squares and means you have to pull ink out of the can you may need to put back in/not use any extra (a nono).

With mine you just continue to pull from the can til the desired amount is reached, add to your slab, put can away.

To each their own!

Sounds complicated, helimited!

I just bought an Ohaus digital scale, I think the SP401. I’ve used the 601 and it works great. I like the idea of using wax paper or mylar squares so you don’t have to clean off the scale after each ink color.

:faceplam: no, it’s incredibly simple. You pull from the scale instead of add to it, thus only taking out as much as you need. How could it be more complex?

Dude, it involves math.

I don’t think there’s a no-no for putting unused ink back in the can—these aren’t chemical reagents of infinite purity-just ink.
The print shop I worked at used 12 x 12 scrap CIS stock (misprinted election signs among others) and there was very little ink lost on the boards. Transferring ink from a lighter “measuring” sheet to a mixing surface might cause problems for some mixes (such as mixing any of the Pantone warm or cool grays).

Transferring ink from a lighter “measuring” sheet to a mixing surface might cause problems for some mixes (such as mixing any of the Pantone warm or cool grays).

What would be the potential issue? Could it pick up stray color somewhere along the way?

No, not picking up stray color, but leaving just a touch left on the sheet. The Pantone grays have the warm or cool color (red or blue) being far less than 1 percent of the batch—sometimes almost measured on the grains beam of an Ohaus scale. This was for offset work and may not be quite as bad in letterpress, but better to keep the small measures on the actual mixing card so that there are no losses between measuring and mixing.

Well, mike, you about summed it up for me. “but better to keep the small measures on the actual mixing card so that there are no losses between measuring and mixing.”
This is why I pull ink from a can on the scale.

But really, folks, obviously you’ll do whatever works for you. I like my method, you will like the one you choose, and so we all use our own ways to make the same loaf of bread.

Printing is like cooking- the recipe will vary with the chef.