The caps
German Outline.
Also called the "skinny banana" by the Montana company. These are the most popular caps there are. The line is medium-thin, the edge is very sharp, the weight is medium. An ideal outline cap. Works great with Montana Hardcore, Krylon, and Rustoleum. DOES NOT WORK WITH MOLOTOW or GERMAN MONTANA. These can be found in three different color schemes as pictured. Their properties seem to be identical, but many people are superstitious about different colors.
(see part III for a comparison between Spanish and German brands of Montana)
Universal cap
This cap seems identical to the German Outline, except that it works with Belton Molotow and German Montana paint.
Astro Fat One of the newest caps available, the Astro Fat is very wide, maybe between an orange dot and pink dot. It is a little wider than the Silver fat cap above. It works best with European brands like Montana and Molotow.
German Pro.
Also called "German 2," or "skinny pro." The two color schemes are the same cap, same properties. Unlike the German Outline, this cap works with Belton Molotow and German Montana, and for those brands, the line has the same properties as the German Outline above. Used with Rustoleum, Krylon, and Spanish Montana Hardcore, the line is slightly wider and softer than the German Outline.
German Fat.
This cap produces a heavy-weight, sharp-edge, medium-width line. It works well with Rustoleum, Montana, and Molotow. It makes a wider line with Rustoleum and Montana than it does with Belton Molotow. It works with Krylon, but tends to cause drips because of the output weight.
New York Thin.
The New York Thin cap is known by many names. New York Outlines, phantom tips, thins, micros, and skinnies. They are medium-thin, semi-soft, medium-weight. They work well with Rustoleum, Krylon, and Montana Hardcore. DOES NOT WORK WITH BELTON MOLOTOW.
New York Fat.
The New York Fats produce a medium-wide, medium-weight, semi-soft line, much like the New York Thins but slightly broader. They look a lot like the NY thins, too. To tell them apart, note the ridges: the Fats have wider ridges than the Thins. Also, the very center of the dot looks a little different. But the ridges are the easiest way to tell them apart. Same compatibility as the NY thins, but does work with Molotow.
Rusto Fat.
The Rusto Fat is named after Rustoleum but works very well with other brands as well, including Krylon, and Montana. DOES NOT WORK WITH BELTON MOLOTOW. Compared to the New York Fat cap, it is slightly wider. Compared to the German Fat cap, it is lighter, producing better results with the cheaper brands of paint.
Black Micro.
The Black Micro, also known as the Molotow Super Skinny (to the Molotow company) and the Montana Super Skinny #1 (to the Montana company) works well with both of those brands and also with Krylon and Rustoleum. With a black finish and a black dot, it definitely is the coolest-looking cap. It produces a very thin line, with a sharp edge and medium weight. Great for doing outlines when you want something thinner than the German Outlines above.
Silver Super Fat.
This is one of the most versatile caps out there. It produces a wide line, wider than any of the caps mentioned above, with a sharp edge. But with Montana and Molotow, you can actually make skinny lines with it by holding the can very near the painted surface. With Rustoleum, the cap still works great for wide lines, but from close up, the line will be too heavy and drip. With Krylon, the cap works OK, but beware of drips--the Orange Dot below may be a better choice.
Needle Cap.
The Needle cap works with Belton Molotow, and as far as we know, nothing else. With Molotow, it produces an ultra-ultra-thin line, not even a centimeter in width, but very heavy. However, it leaves some splatter marks. With Rusto, Krylon, and Montana paint, it produces a wide, ultra-heavy line that drips like hell. Why Montana even sells these caps, we do not know. Perhaps they perform OK with their Alien Art Concept line (see below for more details). But overall, unless you use Molotow paint and desire a splattery ultra-thin line, what's the point? If you don't want the splatter, you're going to have to go over the splatter with another color, and if you're doing that, you might as well just a Black Micro. Anyway, we do not carry this cap, because for all the reasons above, it just sucks.
Grey Dots.
The grey dot is the first in the series of colored-dot caps which range from ultra-thin to ultra-wide. Aside from the Needle Cap used with Belton Molotow, it is the skinniest cap available. It works great with Krylon, Rusto, Montana, and Molotow. Compared to the Black Micro, it is about the same in width, but a little softer and lighter, perhaps making it better suited for drippy brands. It's also good for accents.
Black Dots.
Black Dots are the same as grey dots, but just a little bit wider.
Gold Dots.
The Gold dot is an oddball, you might say. With Montana and Molotow, it is much like the Black Dot but a little wider yet, a medium-thin line. But with Rustoleum, it makes a much wider line. The edge is soft and the weight is rather light, making it an ideal stencil cap. The spray is a little irregular in shape, making it a poor choice for outlines, but it works great for blends.
Blue Dots.
Blue Dots are soft spray like the Gold Dots, also great for stenciling. They produce a medium size line, of a regular circular shape, but the weight is uneven--tends to fill out the circumference and leave a light center. The other strange thing is that the width is narrow when used with Rustoleum paint: the Gold Dots are generally narrower than the Blues, but with Rusto, it seems to be the other way around. Great for stencils, blends, and fills; poor for outlining.
Orange Dots.
Orange dots are fat caps. They are wider than New York and Rusto Fats, and about the same as Silver Super Fats. Works well with all of the brands named above. Compared with Silver Super Fats, the line is a little softer and lighter, and probably a better choice for American brands of spray paint.
Pink Dots.
Pink dots are the fattest cap available. You can make lines 6-8 inches (15-20 cm) in diameter. As you get closer, the weight can get very heavy. Good for filling in large areas (or making giant paintings). Works with all of the brands named above.
White and Black Calligraphy.
These caps have a special insert that creates a "linear" spray instead of the circular spray that the other caps have. That is, the spray will be wide in one direction, narrow in the other. The coolest part is that you can rotate that little insert so the line can be any direction you like--vertical, horizontal, or any diagonal. Great for signing your name, or just creating cool effects. This cap works with all of the brands named above, but the width of the line varies from one brand to the next. It makes a very soft, thin line with Montana, a more medium line with Rusto, Molotow, and Krylon.
Between white and black, we tested them and found them to be the same, with a chance that the white version was slightly thinner than the black one. But it was too close to call.
Red Calligraphy.
This is the same as the Black and White Calligraphy cap, but the line is wider and heavier. With Montana and Molotow you get a medium line; with Rusto or Krylon you get a very big line. The two types of calligraphy caps are pretty similar with Molotow; with the others the difference is significant.
Cap selection and compatibility
There are several factors one should look at in a spray cap:
Width: This one's the only one the novice pays attention to. Obviously, it's how wide your line is. The grey dot is the skinniest; the pink dot is the widest.
Hardness (or, "sharpness"): This determines whether you have a cap that distributes paint evenly across the line (hard), or one that puts more paint in the center and less paint on the edge (soft). The German caps (outline/pro/fat) are the hardest; the "dot" series is the softest. Also, the closer you hold your can to the surface, the harder the line gets. A black dot from 6 inches looks mighty soft, from 1 inch you get a much sharper line.
Weight: This is how much paint comes out. If a cap is too heavy, drips become more likely, but if it is too light, the colors beneath may show through. The brand of paint you use with your cap also makes a big difference--some paints can be light and drippy (really cheap brands often are) and some paints can be heavy and still not drip (Montana). But, all else being equal, the heaviest caps are the needle caps (we don't even carry these, they're so bad); Rusto Fats and Orange Dots are on the heavier side while the grey, black, and gold dots are probably the lightest.
Compatibility: This makes all the difference. If a cap doesn't work with your brand of paint, then what good is it? Some caps perform very differently depending the brand they're used with.
Regularity: Some caps with some brands produce funny non-circular shapes. Among the caps listed above, only blue and gold dots have this problem, and even then, only with certain brands of paint. But the generic caps that come with the cans often have regularity issues.
Longevity: Some caps clog up more easily than others, and some paint causes caps to clog more easily than other brands. Because of the cost, we have not done a long-term study on this characteristic. We would appreciate your input on this. Generally, you can extend a cap's life by cleaning it. If you're in a relaxed environment, consider bringing some Acetone or paint thinner and a little bowl to drop your used caps into; that will clean them out easily. For quick and easy cleaning, you can also turn a can of paint upside-down and spray until paint stops coming out: spray paint cans have a straw that extends from the nozzle to the bottom of the can, and when you turn the can upside-down, you will spray air once the paint is cleared out of the straw, thus sort of blow-drying the cap clear. However, the cost of the lost paint may exceed the cost of just getting a new cap; we don't know. You can also just put your mouth on the bottom of the cap and blow the paint out, but this could result in you getting paint in your mouth which is straight-up sick.
Aside from the Longevity factor, we've done our best to describe cap properties in the description above. Let us know if you have any further insight you could provide. Ultimately, every artist develops his or her own preferences based on experience, and artists of equal accomplishment can have totally different opinions about which caps are better than others (just like musicians and their brand preferences.) The best way to find out which you like the best is to try everything and decide for yourself.
got some images (sorry if there massive i might fix this later) if anyone has images of these caps or others please include in this thread and i will edit them into the thread
if this hepled you please say so below
The Official Cap Thread. everything you ever wanted to know 
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