Actually, TNT isn't dynamite, but in the sewing community it does stand for "tried 'n true" for a pattern that you use over and over because it works for you. I have such a pattern for a long sleeve t-shirt. I made it the first time last year as a muslin for the dress version of this pattern. The pattern is from Sabrina Woman, a German sewing pattern magazine. There's nothing special about the pattern that distinguishes it from the many, many other t-shirt patterns out there, but it works for me...after grading from a smaller size shoulders and upper chest to a larger waist and hips, which is a usual alteration for me.
Here is my latest rendition:
The fabric is of unknown origin. It's a polyester knit but I can't remember where I got it. The polyester is the type that is slippery and "cool to the touch", if you know what I mean, so I suspect it will not be very breathable. That's why this is a long sleeve shirt and not something to wear in the summer. The real downside to this fabric is that a snag is very damaging to the fabric (note to self - do not pick up a cat while wearing it). When I laid out the fabric I found an area about 4 inches in diameter that was all puckered and pilled. It was right in the middle of where I almost cut out one of the pieces, but fortunately I had plenty of fabric and could work around the damaged area. I did wonder if one of my cats "attacked" it but they're pretty good about leaving my fabric and other fiber alone, other than using it as a bed.
The good thing about a TNT pattern is that you can get comfortable enough with it that you can make little changes and still enjoy the bones of the pattern that make it a TNT. For this shirt I made the neckline lower and bound the neck edge instead of just turning it under. For the binding, I cut a 3.5 cm wide strip in the crosswise direction, not on the bias because the knit has a lot of stretch. The length of the strip is 85% of the neckline measurement. I seam the strip at the short end and then pin it right sides together along the neck edge, so that it's roughly 1:1 along the back neck but then evenly distributed along the front neck. I then fold the strip over the seam allowance (I use 1 cm seam allowances throughout) and stitch it down with a coverstitch, although you could use a twin needle on the sewing machine too.
On this version, I attempted to do a FBA (full bust adjustment) but it didn't quite work out for me. I'd never done one before, so I researched it online. Most tutorials I found are for the traditional FBA, where you modify the front pattern piece by adding darts. That method is necessary for woven fabric, but with knits you can add some extra fullness without darts, using a method called vertical FBA. To do a vertical FBA, you basically mark on the front pattern piece where your bust apex is and then draw a horizontal line across the entire pattern. Cut the pattern along the line and separate it evenly across by the amount you want to add. The extra would then be eased in when sewing the side seams - only in the area where you added to the pattern. However, the extra I added seemed to have gotten lost somewhere because my side seams matched too well without much, if any, excess fabric to ease. I cut out most knits single-sided, but perhaps I had stretched the fabric out a bit when I laid it out or its slipperiness caused the fabric to shift. I'll try again with the next one and perhaps add some notches to ensure that I match the side seams accurately.
A non-sewer might question why I'd spend time making a t-shirt, just like a non-knitter wonders about sock knitting. The fit, for one. I hate long sleeve t-shirts where the sleeves are a bit too short or the bottom hem doesn't come down low enough. When I make my t-shirts, not only are those problems taken care of, but I can also make sure that the shoulder seams hit at the right place and the shirt isn't too tight across my waist and hips, and once I get the FBA correct it will fit properly across my bust too. With a (nearly perfect) TNT pattern, I can then focus on the second reason I sew the fabric. I'm more often drawn to a fabric in search of a pattern rather than the other way around. Now the fabrics in my stash that make me think "t-shirt" have a better chance of actually being made...and worn.