Creating exact sized frames

[Tape99]

I am helping my niece with a project she hopes to expand upon.  She gets various sized plastic pieces for displaying pictures.  They are all under the normal 4 x 6 size, but vary in size.  I print pictures on my Canon MG6300 using photoshop to size them using my iMac.  I will get a file of full sized jpegs with a list of the sizes they need to be made into.  Some pics are cropped while others are just resized.  I have created a number of templates that fit on 8 1/2 x 11 photo paper.  I use the Rectangular Tool to make frames with 1 pixel borders.  I type in the H & W using Live Shape Properties, using inches instead of px.  However, the printed picture is not exactly the size it should be.  Often the W is about 1/16" too much and H a little less than 1/16" more than it should be.  I start a NEW document with W: 8.5 in, H: 11 in, Resolution: 150 px/in & at 8 bits.  Is there something I can do to insure the sizing is correct or do I just have to make a frame, say  3.69 (3 11/16) x 4.56 (4 9/16) instead of 3.75 (3 3/4)x 4.63 (4 5/8)?

[Mylenium]

You are messing up the DPI. Working with "only" 150 DPI/ PPI will introduce quantization errors in some cases, because your printer driver's internal calculations get thrown off. Try higher DPI then. That and of course the driver itself might do weird stuff depending on its settings. That's why you should start by checking whether any "fit to paper" options are set somewhere and override them. Likewise, some printers have fixed margins for the transport wheels that may need to be taken into account and/ or likewise need overridden by enabling borderless printing.

Mylenium

[Tape99]

I choose US Letter Borderless or media size and the area printed is scales at 100%, not scaled to fit media.  I will try a few trial runs trying different DPI to see if that makes a difference.  Any idea what my Canon printer's internal default DPI would be?

[JJMack]

Frame have to have the same aspect ratio  that the image being framed has or you need to add a mat that has a cutout the aspect ratio of the image being framed.  You can also made a centered crop of the images the fit the a frames aspect ratio.  Templated can be automaticle populated via a Photoshop script. They are quite easy to create.  Free Photoshop Photo Collage and Mockup Toolkit 

[Tape99]

JJMack,

I certainly don't do anything as sophisticated as this.  After I create my frames, I slide over the pictures and Free Transform them to fit the frame.