How to resize photos to print actual size?

[saul]

<p>I take macro photos of small jewelry items, mostly for internet catalogs. Now, one of my clients wants photos for a <strong>printed</strong> catalog. Every item has to be printed in actual size. Let's say it's a coin. So if you place a real coin onto its printed image they have to match exactly. I am confused. How do I know what size of a on-screen picture matches a printed image. I feel like there should be a simple answer to this. Could someone show me how it is done, please?</p>

[pankaj purohit]

<p>Screen resolution is usually 72 DPI and print resolution is usually 300 DPI.</p>

<p>If you want to show the coin in its real size than you should know its dimensions and than open a new document/image in photoshop and set the desired paper size for the print, don't forget to set the dpi to 300 (while assuming that you are foing to print it at 300 dpi. Now set on the rulers and place the guidelines for the desired dimensions of the object, now open the desired object's image in photoshop and copy it and than paste it into your new document/image where you performed the upper described steps. now resize to match the object's size as the guidelines.</p>

<p>Here is the new window parameters :</p><div></div>

[pankaj purohit]

<p>Here is the example that how to set guidelines.</p>

<p>I am summing that I want to print a coin of 2 inches diameter so I setup guideline between 2 inches, I hope you can understand :</p><div></div>

[pankaj purohit]

<p>All these steps are performed assuming that final print output would be on paper size of 8 X 10 inches at 300 DPI. DPI would effect only in resolution, but paper size should match perfectly in the photoshop with the final output paper which would be used in the printer.</p>

[saul]

<p>Thank you Pankaj very much. I am getting it now.</p>

[jimstrutz]

<p>But what if they are going to print this at 200 lpi or some other printing standard? I think you need to know this first, don't you?</p>

[pankaj purohit]

<p>Jim, your point is right but as I already said that DPI will only affect the 'resolution', not the 'print size'. Paper dimensions/size should be correct, printer will automatically adjust/interpolate the DPI or LPI or PPI. But DPI/PPI/LPI should be fair enough for a decent print resolution. As Saulius is saying that his work is related to jewelry catalog so he should go with about 300 DPI even I would recommend that it should be at least 300 DPI because the jewelry items have very small details so those should be printed very decently. Ofcourse the printer should also be good one here and I think the catalog is going to be printed at a reputed printing service which has some great offset printing devices with sound technicians.</p>