No we weigh it out in grams butter being, for the most part, a solid; we think it's quaint that you measure it by volume.
Solids: Can we at least keep our surface area?
Keeping it light, folks. No malice intended. In a slightly different track, let's disseminate what we are learning here.
in all the European countries I've opened a pack of butter in, it comes in 250g blocks and they have markings for every 25g.
Wow, that is a lot of butter, lol. So if stated in grams, it is universally understood how much butter matter you shall add to your Baked Alaska. And for this purpose, we have these blue lines on the wrapper. Once you get the hang of it, you don't have to read the writing on the lines, anymore, because you will automatically know each line is 25 grams. And if you need more, like say 125 grams, you will just go 5 of these lines, or maybe just use half the stick. But if you think of it like "half a stick," then you will have to know the mass of a full stick. It's easier to just memorize that each line is 25 grams and count up to 5. Cuz this might end up in the middle of a stick, today. But tomorrow, who knows? Half a stick could be 500 grams of butter! And what a mess you have, then!
Nope. Stick with the blue line. It's the only other unit you need to know besides the Meter, the Liter, and the Holy Kg, Amen. This blue line is of course just a print on a wrapper that is so far subject to the whim of the butter company. But soon we'll have a vote to make sure it is compulsory. In case one butter company changes a stick to 298 grams but keeps the blue lines on there as 25 grams per line rather than what it looks like they may be doing is dividing the stick into 10ths, I am sure they will sell just as well as the stick we've used for the last 100 years.
I'm trying to tone it down, but maybe just take my posts not so seriously. Dry humor.
This butter thing illustrates one quirk that is not actually to do with metric vs imperial. I mean, we can do decimal divisions or 10th's in imperial, too. And we can divide a bar of metric butter into quarters and 8ths, if we want. But if you removed the wrapper, isn't it easier to eyeball a quarter of the bar than 3/10ths?
This whole divide is affecting the way we eat. We are undoubtedly artificially or subconsciously rounding over our recipes to match with blue lines of decimal (or factors of 2^-1 in imperial). This is causing some loss of culinary excellence due to error introduced by measurement bias.
With the metric butter, it would indeed be easier to convey higher precision than the American stick. Leave the marking alone, rely on the fact that the bar IS a standard size and will be for the length of relevance of the cookbook, and state the amount of butter in % of a stick. Just switch from thinking of each line as 25 grams. And think of each line as 10% of the bar. So "add 37% of a stick of butter?" 3.7 lines of butter?
Cuz you know, 25 per is not metric. It is not factor of 10. This blue line is basically like a "tower oz" of butter. If the recipe calls for 75g, this doesn't change into a 3, no matter how many times I shift the decimal point. But 30% is kosher. If you guys were serious about your metric, you would only sell butter in 1kg sticks, so your blue lines can be centagrams and the Plan will be one more step towards completion. A centagram is obviously a way better unit than a blue tower line of butter. The situation you have now, you're basically using 10ths of a 1/4 of a base unit of a kg. That's such an imperial thing to do.