I bought the 3-pack of the Wool & Prince (W&P) undershirts. I'm very satisfied with them and definitely recommend them. The fabric is soft and luxurious against the skin - the knit fabric thickness seems similar to my cotton undershirts, but these are preferable for sure - they are warmer, softer, and just more comfortable to wear than cotton undershirts.
Observations: The length is much longer than standard cotton undershirts - I have an average length torso and the hem on these undershirts goes to the very bottom of my rear end. (The length down the center of the back from the top of the collar to the bottom hem of the shirt is 32".) The "natural white" color is definitely more of a cream color - it looks like a very, very pale yellow when I lay it next to my bleached white cotton undershirts. Because it has a generously-sized v-neck, it does not show when I wear it with my button down oxford style dress shirts and keep the top two buttons undone - so kudos to the designers at W&P for getting that detail right.
Like the title of this review states, these are the best 100% merino wool v-neck undershirts that I have found. The only other source that I've found is Joe Merino (JM)- based in The Netherlands. I tried their offering and I prefer the W&P undershirts. I am not affiliated with either brand, and I offer you the following unbiased comparison:
Fabric Weight: W&P uses 150 gsm; JM uses 210 gsm. (Current offering) I prefer the W&P for year-round wear.
Fit: W&P is a relaxed fit; JM is a tighter "fitted" fit, even the JM XL is tighter than the W&P offering. W&P gets my vote.
Length: W&P size L is 32" long; JM size XL is 32" long (both are too long in my opinion)
Shape & Size of V-neck: W&P is a well-formed V sized correctly; JM is more of a U than a V, and it's even larger. Neither shows under an unbuttoned shirt. W&P wins again.
Color: W&P is a very, very pale yellow or "cream" color; Side by side, the JM is noticeably closer to white than the W&P. My preference for color goes to JM.
I think there's room for improvement with the W&P offering, and that's why I didn't give it 5 stars. 1. The color can be improved to make it nearer to white than it is. 2. The length can be shortened to make it the traditional length of most cotton undershirts. (I recommend shortening the size L to 28".)
With all that said, they're still the best offering out there right now, and I'll be buying more W&P undershirts when I need them. They are a luxury item for everyday wear. They're much more comfortable and more resistant to stink than cotton undershirts. I certainly hope W&P keeps making them for years to come!