The short version: I've updated Late Winter Snowflake to include extra information about chain tension, with the hope that it will help the pattern lay flat. The revised pattern can be found under the old link on my patterns page.
The long version: Let's talk about chain tension
Since I began tatting, I've changed my tension a few times. When I refer to chain tension, I am talking about how tightly I pull my core thread after finishing a chain. For the sake of simplicity, I've separated tension into three options: low, medium, and high. All three samples are tatted with the same stitch count:
Low tension: In the example below, I've tatted my chain in the usual fashion, but have not tightened it at all after finishing. I do make sure to snug my stitches together while I am tatting, so there is a small amount of curvature here:
Chains tatted with low tension are slightly longer, but also have the most flexibility. I can manipulate them much more freely than chains with high tension. One must be careful, however, because chains with too low of a tension have a tendency to become pointy at picots and thrown rings, or floppy and unstable if there is no tension at all.
Medium tension: In the following example, I've tatted a chain and finished it by pulling the core thread to form a slight curve. I'm careful to stop just after the curve is formed so that my stitches don't get overcrowded and my chain maintains good mobility:
Chains tatted with medium tension have a balance of flexibility and curvature. This is my preferred method of tatting chains.
High tension: Here, I've tatted a chain and pulled the core thread tightly upon finishing. My stitches have just begun to crowd and there is a very steep curve:
Chains tatted with high tension have the least amount of mobility. They create a nice curvature, but can also limit the flexibility of a motif so that it will need to be dampened and blocked to lay flat. I've had a lot of problems when tatting with high tension, so this is my least favorite method.
As you can see, chain tension is highly variable. This poses a unique challenge when trying to design patterns for a diverse group of tatters. We each have our own habits, styles, and visual preferences, so what works for some will not work for others. I hope this has given a glimpse into my style of tatting, and what you can do with chains, for those who may be interested in such technicalities :)