The logo is the most important element for identifying your packaging!
Usually logo files are provided in vector format.
Portable Document Format (PDF)
Adobe Illustrator (AI)
Encapsulated PostScript (EPS)
Scalable Vector Graphics (SVG)
The image in these files is stored in the form of elementary geometric shapes.
The advantages of such formats are that objects are easily scalable, without degradation of quality when enlarged. Also, objects in the files can be easily recolored in any colors, simply edited and modified. In addition, such files are small in size. Moreover, they are easily converted into raster format, something which cannot be said about the reverse operation.
It should also be understood that by placing a raster element in a vector file and saving it in vector format, you are not likely to get a correct file suitable for further polygraphic reproduction. When a raster fragment of a logo goes into a vector file as a container, its properties do not change. However it may originally be of the wrong color model (for example, RGB) and the resolution may suffer if it is less than 300 dpi. So, before anything, you have to check the raster resolution for the current size (300 dpi) and color model (CMYK+Pantone).
There are certain technological requirements for logo images that depend on the printing technology.
To print your logo, offset printing is probably the easiest option today. As I wrote above, it is 99% enough to check the file resolution and color model. The rest depends on the skill of the printer. However, you should remember that the minimum dot diameter that makes up a printed offset image is 7-8 microns. Do not make logo elements smaller than this size.
For hot foil stamping, silk-screening, UV-varnish the recommendations are:
1. Thin lines must be at least 0.3 mm thick
2. The non-printing area must be at least 0.4 mm
3. When using cover materials with a modified structure (texture of linen, verge paper, sand, etc.) requirements are stricter. The minimum is 0.4 mm. It is not guaranteed to achieve a perfect result when you mix thin lines and spaces with dimensions bordering on the limits as they might not print or stick, which is unacceptable for a logo. The logo must be perfect!