Paint Splatter

Could be several things.

The paint could be drying between the nozzle and the surface. You can help this by spraying at a lower pressure or closer to the surface of the model. You can also add a drop or two of acrylic retarder to your paint.

You could be getting "Dry Tip". Look for buildup on the tip of your airbrush and anytime it's there wipe it off. Acrylics are notorious for this.

The fine nozzle may be too fine. Not sure what airbrush you have, but from what I've read some of the finer nozzles are just too small for the pigments in the paint we use.

You may need to thin the paint a little more. Finer nozzles typically need slightly thinner paint.

When you say, "Spatter" are you referring to a dry spatter that looks grainy or are you referring to more of a spider-web looking spatter?

Scott gave you some good points to check for but I am wondering if you are spraying at too high of pressure or maybe too much thinner?
What thinning ratio are you using (paint to thinner) and what pressure?
How far away are you also?

Mike

john, i tell you the truth and dont mean to be discouraging, but its gonna be very hard to get a consistant fine line with the H. it was for me anyway and i finally switched to a double action brush for tons more control when doing fine line cammo jobs. but, you need to thin the paint down to minimum 50/50 and even thinner if this doesnt work. then, like scott says, lower the pressure down to around 12 and keep lowering it if this doesnt work. get in close to the subject (1/4 to 3/4 inches from the surface being painted). if you are using tamiya, thin with tamiya thinner as i've found that this works best, if you dont have tamiya brand thinner i would try distilled water before i used windex as this has amonia and breaksdown the paint instead of thinning it. rubbing alcohol works to but it will tend to dry faster and cause even more tip dry. tamiya brand thinner has retarders already added to the mixture and it works great....or has in my experience with it. i've laid some very tight free hand cammo with tamiya acrylics and is my favorite acrylic when it comes to airbrushing. later.