How about you just use a template? I do that a lot when a client requests a cookie with a pretty difficult/precise logo or image on it. You just cut out the negative shape of the design in a plastic or velum template and then you "stencil" on the colour using a paint of lustre dust/vodka or lemon extract. In a few hours, you can go back and add all that thin black piped detail around the numbers.
Works like charm!
In your case, I'd ice the cookies in the red, let them dry very well overnight, lay the stencil of the "49" on top and using white lustre dust mix just stipple the colour on thinly and not too wet. Let them dry and add the black outlining.
Here are examples of cookies I've done using this technique. It's super-easy to do, totally edible and saves HOURS of time trying to pipe a complex pattern over and over again onto hundreds of cookies!
These cookies look great! Can you tell me how do you get the negative image? sorry I am very new to all of this. Also can you explain this process once more to me...I am a little confused.
It's just like stenciling. You make a stencil and you cut out the areas that you want to be coloured, but you leave the plastic where you want the white.
Using lustre dust + vodka as the "paint", you use a clean stencil paint brush (round with bristles all the same length, available in any craft store) and you literally just stipple the colour on through your template exactly as you would do if you were stenciling a cupboard door or any craft project.
Here's a photo I just Googled on the web to show how people use a stencil....except you'd just put your cookie underneath and use an edible lustre dust as the paint.
Is it always Lustre Dust that you use...do you ever use just another color of the RI?
I cant find the thread but there is one here about stencilling on cakes. They have a link that shows videos re: stencilling with buttercream and royal icing. You can use pretty much anything u want - it doesn't have to be luster dust.