Why don't jpg pictures open?

I am a graphic designer and i am trying to explain to a client why she has to send me the pictures in jpg.?

• ok. i found this gig of laying and designing a math book using Indesign software. i need to prepare it and send to print for this teacher. she sends me every component as a word document. including the pictures and vectors. i have been working for years as a graphic designer and i know for a fact that the pictures she has sent me are way to small. to increase the size of some of them i have to increase them to a 200%. altough most of them do not exceed 4 inches wide and tall, there are 2 hundred of them and the document will be too heavy for In design, if i dont call the pictures through the software. i keep on telling her she needs to send them to me as a jpg or tiff format. still she questions to me why. how can i explian to someone who knows squat about design that she needs to send them to me on those formats??

• Answer:

  The only real answer is to explain resolution and the minimum required for offset litho printing (absolute minimum is 250ppi at 100%). Word will always embed raster images and will make them low resolution and RGB. Finding a reasonable explanation of resolution that a lay-person can appreciate is difficult perhaps the best way is to show what happens when a low resolution image is printed – not always easy to lay your hands on an example. The trouble is that people often don’t keep the images they insert into a Word document (or know where they imported them from) and do not appreciate that the image files are necessary. And sometimes all you can say is that you are a professional and that your advice is that the images are not of a good enough quality, explain that you can re-draw images (where possible). Ultimately if the client is not prepared or unable to supply the images then you are left with no alternative but to print what you are given with the written agreement of the client that they will accept poor quality (that usually makes them think).