When to use a foundation like paper or muslin...
 

I've seen videos and patterns where strip piecing and/or 'wonky' log cabins are done with and without a foundation paper/fabric but don't understand when it is necessary or not. I'm attempting a wonky type of block (my own design so no directions!) and would like to hear what you think. If I should use foundations in the blocks, why?

Foundations (whether paper or fabric) are great when .....

1) The piecing is tricky/tiny/delicate/intricate - paper piecing helps with accuracy
2) You are using "uncut" strips like strip piecing. You can use either paper or fabric as a foundation and just add the next strip to the piece and keep going. A lot of strip blocks are made with non-uniform pieces of left over strips and using a foundation helps you manage the size easier.
3) The project will take a looooong time and you want to keep the finished blocks "stable". You can piece them on paper or fabric foundation, baste the final edges and set the blocks aside for another day. The blocks will retain their shapes nicely.

Right now, I am making a paper pieced border for my quilt. The border I chose, would have been near impossible to piece with any accuracy, without the paper piecing. But I have never used paper or muslin when I make string blocks. I just don't seem to have any problems with them. If you go to Quilterscache, many of the blocks give you the option of either traditional piecing or paper piecing.

Why don't you try one block using paper piecing and one without. See which technique gives you the look that you are trying to achieve and which one is easier to do.

I love paper piecing for making intricate or complicated blocks, esp. those with points. (My Storm at Sea quilt came out so good using paper piecing.) It's using paper just as a foundation for support that was throwing me. I've put a few of my wonky blocks together now, without using any foundation, and they are coming out fine. I guess I'll just go with a 'try it and see which way works best' approach.

I'm no expert. I would use paper only for paper piecing where printed foundation piecing pattern is used. It is great for getting sharp points and accuracy on complex designs.

I would use a muslin foundation for crazy quilting. I haven't made a string quilt, but would probably use muslin for that.

I have used foundation for string quilts. Since using scrappy strips it helps to know when you have enough to make a block. Also helps to keep those strips not on the straight of grain from stretching. I prefer muslin for this so I don't have to tear away the paper.

I use paper for tiny complex blocks or if I am having to deal with a lot of bias edge.

I agree. If I do decide to use a foundation for strips, I'll use muslin as I hate removing the paper. When doing paper piecing of blocks where the pattern is on the paper, I use the method where you fold and sew along the cloth side of the paper and not on the paper itself. I can then use the paper foundation a few more times, saving on printing and paper. Works for me. Thanks for your response.