Making add-ons for my mod?

Hi,

So basically, I made a mod, and want to make a separate mod that shares items (Like a item in mod 1, is used in mod 2)

I tried exporting my mod twice. Once with mod 1 items, and once with only mod 2 items.

But the mod 2 item's textures are missing (black and purple).

How would I do this?

Please help,

Thanks :)