standard yarn weight system questions

[catwoman]

Hi.I was wondering if a person could not go by the yarn weight system?Do you guys always go by the standard yarn weight system?did anyone here ever use a different yarn weight than the pattern?  Like i want to use a different yarn weight to make a round ripples bigger for a blanket

[Bailey4]

Yarn weights are not set in stone.  For instance it's my experience that worsted weight acrylic yarns have a spectrum within their numbered weight categories.  For instance if I make a swatch of Caron Simply soft and I make one of Caron Pounders which are both a 4 the size of the swatches are not the same.  I can play with the hook size to make it larger but it has been my experience that Simply soft creates a slightly smaller swatch so I have to account for that when making projects.  When possible I like to know what type of yarn an original pattern used because it can help me match the gauge of the pattern.

As for using a different weight many people do that both going larger and smaller to achieve an effect but you have to be willing to experiment to see how the weight of the yarn and the hook size you use effects the pattern you choose.

There are always changes.  For instance you can use a heavier yarn but understand it will make for a heavier blanket.  That might not be an issue, but I ended up frogging a blanket at one point because it weighed a ton and was not appropriate for the gift I intended.  In this instance adding rows with a lighter yarn was a better choice than a heavier yarn that worked up faster. 

[redrosesdz]

It depends on the pattern. Something like a round ripple can be made with any yarn thickness. You just have to use a bigger hook for thicker yarn.

[Granny Square]

Well, yarn weights are 'set in stone' in that they are set by national standards, but the 'stone' for each yarn class is a range which can affect gauge within the same weight class - see this wraps per inch scale https://en.wikipedia.org/wiki/Yarn_weight

Something like a blanket or toy, that doesn't have to be an exact size (like a sock must be for example) can easily be changed up with a different weight and hook size.  Be aware, though, that the yardage given for the pattern may vary considerably from what you'll need to complete the project if you make changes.  Example, I made a project recently using US #2 where it should have been US #3.  I used the 'right' hook per pattern but had to make many more repeats to get the required size, so that wasn't a problem, but I ended up using nearly 3 TIMES more yarn yardage.  I don't know of a guide to tell you how much more or less you might need if you switch yarns up or down, I'm sure it depends on the stitch pattern and your tension.  I'm fairly sure the 3x wouldn't have worked in the other direction, in other words would I have only needed 1/3 as much yarn if I used #4 weight - that would have meant a 6' wide triangular shawl made from less than 1 Red Heart Super Saver's skein's yardage, which seems doubtful .

Another thing to consider, since you mentioned 'bigger'... if you used bulky yarn instead of worsted weight, you may need less yardage but would there still be a negative cost differential -  bigger yarn  is more expensive per yard--does that cancel itself out?  I don't know the answer since there's so many variables, but something to consider.