Having issues painting missiles

You could seal the tape edges with some clear. Solid color decal material
is another possibility.

I paint the base color and put tape on one of the sides of the stripe, brushing the stripe color away from the tape. I then add tape and paint the base color again until the part I don't want is invisible

I got lucky once and used a left over decal. It was a wide fuselage band from a Typhoon (I think) and i cut it into strips to make bands for missiles. Depending on the band color (Missile) you could also use a left over tail flash etc. Just check your left overs. Just make sure you use an accurate measuring tool, I use a 6" machinists steel rule that goes down to 1/64" (.0156").

I hope you don't mind me sticking my nose in here. I may be way off base but there was a tip in the Dec. 2002 issue of FSM from H. Scott Edwards on striping bombs for a B-52 he was building.

He used a small DC motor powered by a couple AAs and a piece of wood doweling. Drill a hole in the dowel to fit the shaft on the motor. Cut an X in the other end to fit the fins on the bomb/missile. Put the motor in a vise, stick a bomb/missile in the X and paint the stripe with a fine brush.

You could probably find a way to do the same thing with an electric screwdriver, drill motor, etc.

Of course, if you're talking about painting stripes lenghtwise, that won't work and I now look like a total idiot.

Decals are the way to go. Use black, yellow and brown decals and use a new #11 blade to cut them into strips. It will give a much better looking, sharp lines for the missiles. Check your references on where to place the colored decals, as not all missiles were marked the same.