Confirm the exact outside dimensions
Four by six inches is exactly 101.6 × 152.4 mm. A product described as 10 × 15 cm is 100 × 150 mm. They share a 2:3 ratio, but they are not the same physical size. Read the product or frame specification when an exact fit matters.
Landscape orientation is 6 × 4 inches; portrait is 4 × 6. Rotating the target changes which edge is horizontal, not the physical area or ratio family. Make sure the photo orientation in the preview matches the composition you intend to print.
Check the source shape and pixels
A 3000 × 2000 landscape file already has the matching 3:2 shape. It fits a 6 × 4 print without a necessary crop and gives 500 PPI. A 1800 × 1200 file has the same shape and gives 300 PPI. Neither example tells you whether the source is well focused; inspect the image itself.
A 4000 × 3000 file is 4:3. Filling a 6 × 4 frame removes height, retaining an ideal 4000 × 2666⅔ region. The removed area is about 11.11%. If the top or bottom contains important detail, compare fit before you commit.
Keep the whole image when edges matter
The complete 4:3 photo fits inside 6 × 4 inches at 5⅓ × 4 inches. Centred placement leaves one-third inch on the left and right. Those borders are the consequence of preserving the original shape, not an export failure.
When ordering from a lab, review its own final crop and border controls as well. A correctly prepared file can still be treated differently by a service that fills its output automatically. PrintLilt does not send an order or control a separate provider’s settings.
Separate the photo from the paper
For home printing, a 4 × 6 image can be placed on a larger sheet while retaining its exact dimensions. On portrait Statement paper, a centred portrait 4 × 6 image leaves 0.75 inch at each side and 1.25 inches above and below.
A6 paper is not an exact substitute for 4 × 6 inches. Its 148 mm long edge is shorter than the photo’s 152.4 mm edge. Scaling the image to fit A6 changes its physical size, even if the result looks almost the same on screen.
Check the physical result
Export a layout PDF when the page placement matters. Match the loaded paper to the PDF, choose actual size or the equivalent 100% setting, and inspect the print preview for clipping. A Fit option can reduce the page to the printer’s usable region.
Measure the calibration mark and one photo edge on a first print. If they are smaller than intended, correct the print settings instead of changing the source pixels. Keep your original and save the layout so another copy can be made from the same measured setup.