Most people don’t understand the types of construction of the different alloy rims and their benefits and problems. There are essentially three types of construction methods.
All alloy rims are extruded. Molten aluminum is forced through a die that gives the rim it’s shape. The extruded pieces are straight “bars” about 15 feet or so long. These are then put through a roller that forms a coil of about 4-5 rims. The coil is then cut with a saw. All alloy rims are made this way no matter what happens after. It’s the extrusion process and the fact that the join area is the connection point that connects the tube but it’s mating two surfaces that are the circumference of the rim apart on the extruded bar that virtually always results in irregularities at the join area. Usually these are minimal but they are always present.
There are three basic ways to join the rim - pinning, sleeving and welding. The pinned rim uses an extrusion that has two small (about 1/8″) channels running the entire circumference of the rim. This is a strong system but it’s also heavy because you have two extra channels. The sleeved rim uses a small sleeve that is inserted into the join and glued (epoxy). The sleeve is created by a different die and very closely matches that interior of the channel of the rim. Welded rims are similar to sleeved rims except they are welded instead of being sleeved.
Neuvation uses sleeved rims because they are less costly than welded rims and allow the use of a thinner wall (because it doesn’t need to be welded). The only possible advantage of a welded rim is that there is no possibility for there to be a bump at the seam. The bump at the seam - which is possible with the sleeved rim - is easily fixed with some light sand paper.
All quality alloy rims have machined braking surfaces which greatly improve braking performance. Virtually all alloy rims are also anodized. Painting would not be as durable and add a lot of weight (probably about 50 grams per rim).
Because of the extrusion process, rims vary in weight by 30-40 grams. We actually weigh all rims but that only eliminates the heavy ones. There is still a variance. People ask why not just only accept the lightest rims? Because it would greatly increase the cost. The more critical you are of any process the more it will increase the cost. Sometimes it’s important and other times it’s not.