i'm working on a pinwheel quilt for a friend's upcoming baby and so just finished piecing 256 half-square triangles (HST) using the triangle papers. coincidentally, right before starting my HSTs, i had just read this post from Minick & Simpson where she had also worked on HSTs, and it helped me be more thoughtful while working on mine. so this isn't a tutorial per se, just some thoughts while cutting and snipping and ironing and sewing my HSTs :-)
trimming dog ears are such a pain--literally and figuratively! my wrist is still sore from snipping fabric 512 times (years ago i had tendonitis because of cutting fabric and i'm still prone to it--eep!). but if you're using the triangle paper, it's a tad easier to fold the paper over and then trim according to the paper (hopefully the photos are a little clearer). this has the added benefit of weakening the paper before tearing it off. of course, i didn't figure this out until i was 2/3 of the way through!!! (btw, in my Miss Read books, i'm always reading about how they "top and tail" gooseberries--i've never seen anyone do it, but i see myself "topping and tailing" my HSTs :-)
the white is the paper, not the background fabric. when you fold up the paper, you have a nice sharp edge as your guide to cut off the dog-ear.
i've been reading alot on the blogs about pressing open the seams (vs. pressing to one side) Carrie Nelson of Miss Rosie does it and i'm a huge fan of hers so i thought i'd give it a try. but i gotta say, i don't like it. it's just too time-consuming to have to press open the seam from the back, and then from the front to smooth it out--way faster to just press to the side. (this probably speaks more about my lack of perfectionism than anything else :-)
i thought i would at least try pressing open the seams with the pinwheel block 'cos that middle section, where it all comes together, gets awfully bulky. i did one, and while yes, it does lie nice and flat, it takes longer and i would need to pin the blocks together while sewing.
i found that being consistent is the key with these pinwheel blocks. if you always press to the dark (just for example's sake, i guess you could also always press to the light if preferred), then all the seams will nestle together (so you don't have to pin) and you would still get a flat block. it also makes it a no-brainer while sewing--just make sure your blocks line up exactly the same as the previous one, and you're on the right track.
1) press to the dark always.
2) you can sorta see how the two seams will nestle together.
3) when chain-sewing the HSTs together, note that the white fab is always on the top left. it becomes a no-brainer to sew--otherwise you may sew the wrong sides together (been there, done that :-)
4) it also helps to lay out the fabrics exactly the same while pressing--again press to the dark. i learned from Simply Quilts, to press blocks on top of each other, that way the bottom blocks get the extra benefit of additional heat as the newer blocks are being pressed.
5) when sewing together the sides of the pinwheel, the opposing seams nestle together quite nicely so you don't have to pin....
6) though it really helps to have a stiletto to push the seams through the sewing machine. i only recently got this stiletto (from Daiso) and it's helped tremendously in matching seams.
finally, when pressing open the 4-patch, which makes the Pinwheel block, you do that little twist on the back which pops open a couple of threads (i love it when i can hear the little "snap") --sorry, i can't explain it in words more than that--and then the other seams will also magically lie towards the dark, and you get the little pinwheel in the back. this will make it way easier when piecing all the blocks together because you'll get the opposing seams that nestle nicely together.
i like the pinwheel block for a baby quilt 'cos it's so colorful, it looks like a lot of work (though it's mostly just tedious), and you don't have to sew thousands of HSTs (for a bed-size quilt), just a couple of hundred :-)
this is probably really basic info for most of you guys, but hopefully it'll be helpful!