Hello
I recently bought a blue jacket (inside there is a different colour) and trousers, and I wonder if I were to install a topit inside, should it also be blue?

It should be the color of the lining.

Should we be talking about such things in open fora?

What's a topit? Is that a new kind of dessert?

Thank you Jim, sometimes the lining has an odd colour, but I know what to look for now. Still, might be tough to put it all together.

If you're not into sewing, try using fusing tape from a sewing store and you can just iron the fabric together.

Personally I prefer sewing, because if my topit is poorly made, then I can unsew it.

I have one more question, what is the appropriate horizontal length of the lower part of the topit?

It bothers me because I have two clips already at this side of the jacket (for cards and a silk), so if I keep them here, my topit at the bottom line could have 17 cm (6.6"). Still I could stretch it at the upper line to 20cm (7.8") above the clips.

I will use Michael Ammar's pattern or something similar, possibly longer in the upper line.

Many magicians attach clips to the trousers but I was taught to use my jacket, because I can lift it without flashing the clips. Is 17cm enough? I don't want to mess my jacket.

On the other hand, use the fusing tape to test the dimensions. If they are correct, you can just sew right over and through the fusing tape. If not, no harm done if you need to shorten the measurements. Just sew inside the fusing tape and then remove the fusing tape and the excess fabric.