Multibond is a light-duty version of Kimberly Clark's most popular fabric, Evolution (Technalon). Light duty means just that...it is similar in structure to Evolution, but is three layers of bonded polypropylene rather than four. It has only a two-year warranty against deterioration from ultraviolet (UV) exposure, while both of the other Kimberly-Clark fabrics (Evolution and NOAH) have four-year warranties.
Good:
It rolls up much more tightly than Evolution, although not as tightly as Ultralon. It's moderately water resistant, and it is the least expensive of all the car cover fabrics. This, combined with the fairly good warranty, makes it a good value for the car cover buyer who isn't overly demanding.
Bad:
It is EXTREMELY light and can be difficult to handle in a breeze... especially in semi-custom versions that do not have mirror pockets. It suffers from the same response to UV deterioration that Evolution does, in that it tends to deposit itself on the car as a dust that is not easily brushed off as extended exposure to sunlight begins to break it down. In the case of Multibond, this deterioration begins even sooner than it does with Evolution.
Evolution IV is the current version of this very popular fabric from Kimberly-Clark...while a bit better than III, it is basically the same material, which is a four-layer bonded polypropylene fabric. It has a much better warranty (four years) than the older version, but it's still Evolution (aka Technalon), albeit an improved version.
Good:
It's very water-resistant. The current version has a 4-year manufacturer's warranty. Due to its thickness, it offers some resistance to parking lot dings. Mid-priced - lots of protection and warranty for the money. Evolution is available in three colors (tan, blue, and grey) in custom patterns.
Bad:
It folds up extremely large. Compressibility is miserable. It can be somewhat hard to deal with in a breeze - even a fairly mild one. The thing I like least about it is that it is not really a "fabric" at all but, rather, a hot-pressed "bonded" synthetic. As a result, it isn't particularly sturdy. For example, if you wash an Evolution cover, you're best to do it, and you MUST dry it, on the car. Needless to say, washing the cover this way makes a mess of the car, and now you have to wash it too. Don't ever put one of these covers in a dryer or you'll regret it. Its structure is not intended to survive the rigors of a clothes dryer. NEVER put Evolution in a heated dryer - it WILL melt. Although it can be machine-washed, washing machines don't really do it any favors either. Also, your exhaust will melt it if you let it touch the hot tip just after shutting the car down. But the worst thing about Evolution is that it begins to chemically break down after about one-and-a-half to two years of heavy exposure to sunlight and starts leaving a filmy residue all over the car. This isn't something you can just brush off with a California Duster either. It needs to be wet-wiped or washed off. With Evolution IV, this is the time when you use that excellent warranty. Covercraft, the largest-volume manufacturer of car covers, replaces a sun-damaged cover that is under warranty with a new one for only the cost of shipping (usually $10).
NOTE: Although it is the thickest of the various car cover fabrics, and is, therefore, often picked by owners as the one best suited to protecting their cars from cats, cats LOVE this fabric (odor?, texture?) and will tear it up mercilessly. Cat damage is NOT covered by the warranty. Never buy a cover to discourage cats from scratching your car. Find another way; car covers in general are not the solution to this problem.
NOAH is the newest bonded polypropylene fabric from Kimberly-Clark. Originally marketed as waterPROOF, it is the most water-resistant fabric available for car covers. Although the manufacturer has since backed away from the "-PROOF" statement, it's still better at keeping out water than anything else out there...apparently even Ultralon.
Good:
Very, very water-resistant. Despite this water-resistance, NOAH still breathes a bit better than Ultralon. Usually, NOAH can be found at prices that are slightly less than Ultralon. Four-year manufacturer's warranty. Thinner than Evolution and, consequently, rolls up smaller, but not as small as Ultralon.
Bad:
Like Multibond, NOAH is pretty light and can be difficult to handle in the wind. Being a bonded fabric, it is not as sturdy as woven fabrics, and should be handled and washed carefully. Although the fabric is new enough on the market that no empirical longevity information is yet available, it's probably reasonable to assume that NOAH's response to ultraviolet exposure will be similar to Evolution's.
A blend of cotton and polyester, either lined or unlined, that is best suited to indoor storage of vehicles. Owners of restored show cars often pick the flannel-lined version, as it is very soft against the surface of the car. NEVER buy tan flannel cover for a convertible with a canvas top. The flannel will leave itself all over the canvas and you WON'T like the work involved to remove it. Tan flannel works well with vinyl convertible tops, however.
Good:
It's heavy enough that it is relatively easy for one person to get on and off without dragging it in the dirt, even in a fairly stiff breeze. It folds up smaller than Evolution, but not all that small, especially if flannel-lined. The lined ones are VERY gentle on the car. It is a true fabric and, consequently, may outlast Evolution covers (at least mine have) despite the underwhelming warranty coverage (1 year, prorated). Also, because it's a fabric, it can be machine washed and dried without being destroyed.
Bad:
It isn't even a little bit water resistant. Although it rolls up fairly small, it's much less compressible than Ultralon. Being a fairly open cotton weave, it accumulates dust and then lets it through to some extent, and the flannel lining will flock a bit on the car, causing you to have to CA dust the car every time you take it off after you've used it for a while, providing you're as picky as I am. At least this is just dust that comes off easily with CA dusting, unlike the residue that Evolution leaves behind when it gets older.
Ultralon has had some water repellency problems and is becoming less and less available as a result. Some vendors, Covercraft among them, are not offering it at all anymore. They are now offering a new fabric, WeatherShield, instead. If you want to know more about this new fabric, visit the Covercraft Web site at http://www.covercraft.com/weathershield.htm . There is also a link to the manufacturer of the fabric, Nextec, at the bottom of the page.
Sunbrella is the king, the absolute top-end, of car cover fabrics. An acrylic canvas similar to the fabric used for boat and sail covers, but softer for vehicle applications, Sunbrella is about as impervious to ultraviolet damage as a fabric can be. Featuring a five-year factory warranty against sun deterioration, it lasts more like eight to ten years in actual application.
Good:
Extremely sturdy, long-lived, and easy to handle in a wind. Opaque to sun and will not pass dust, even thoughit's a woven fabric. Comes treated for water-resistance, and can be re-treated during the life of the fabric. Virtually indestructible in the face of the elements. Excellent warranty; even better real-life longevity. Even easier to handle in the wind than poly-cotton. Available in six colors.
Bad:
EXPENSIVE - approximately twice the cost of Evolution (doesn't look as expensive when the initial cost is amortized over the life of the cover, however). Relatively heavy; could be considered hard to handle due to its weight by small users.