Here is simple solution to create single PDF by combining multiple files from various files types.
Assumption: I Assume you have 10 png files that you want to combine in to single PDF file.
Note: It really doesn’t matter if those 10 files have different height & width dimensions.
Here is how to do this:
Step 01: Locate & Open Preview in Applications folder on your Macintosh
Step 02: Select Preview now go to File > Open
Step 03: Select & Open all desired files in Preview
Step 04: Go to View > Select Thumbnails. Now you should be able to see thumbnail of all opened files in left sidebar of your preview.
Step 05: Select all thumbnails in left sidebar by clicking on first thumbnail & then pressing Command + A, Now Go to File > Export Selected Images to batch process to convert file type of all png files to PDF > Now click on Options > Under Format choose PDF > Click ‘Choose’ to choose destination of for saving files
Step 06: Now open that first newly created PDF file in Preview & Now go to Edit > Insert > Page From File… > Now locate & select those remaining files & insert it in current PDF file
Step 07: Now click on Save to save your PDF with changes you have done & page you have inserted.
You are done with creating single PDF by combining multiple files & documents using Preview on Mac OS X.
Hope it helps,
Thanks & Regards