It is better to save in psd or tiff, because they preserve the value, while in jpg, the compression recalculates the image every time and discards the "excess" colors. Therefore, with several series of corrections, we degrade the image.
PNG is primarily intended for the web; its feature is the "transparency" of images - where it is not "painted", the image is translucent, transparent. Great for logos. However, it is better to use photographs in jpg or gif.
A logo or drawing can be printed in vector or bitmap format, or in a record. If the image is bitmapped, this means that it is composed of bits, pixels, dots. On a certain scale, there armenia telegram lead are so many dots that record colors and shapes. If you increase such a record to a tenfold value, then we have 10x fewer dots on the same scale. In other words, one dot is 10x larger. When printed, this means that the image becomes blurry and "pixelated", dotted.
that the illustration, image or logo is written in mathematical form as a line shape. As the file is enlarged, the notation formula remains the same and the edges are always sharp, regardless of the magnification, depending only on the device that prints (if the printer is 600 dpi, so is the sharpness; this is taken care of by the RIP - raster image processor).
Everything I wrote about vectors and logos also applies to files within PDFs. People often say to me, "But I sent you a PDF in vectors." If the image was saved in bitmap format before the PDF was created, it will also be saved in bitmap format in the PDF. This means that if you print the PDF magnified by 10x...
Since it is not possible to simply convert an image from bitmap to vector format, it is very important to give the designer clear instructions to prepare all materials in vector format . The reverse is very simple.
I occasionally give a lecture or workshop on this topic. We look at the entire process of marketing decisions for print, including another important topic that didn't have space here: CONTROLLING PRINT COSTS.
I also show many concrete examples at the workshop, and as a gift I give away our print and paper catalog, where we printed the same image on several different materials and several different technologies.