When printing or purchasing photographs, there are various paper and coating options. Glossy photos are shiny and smooth while matt photos are dull and textured. A lustre finish (more commonly spelt "lustre), is in between the two, taking characteristics from both. Deciding which to use depends upon how you will use the photograph, the image in the photo and personal preference.
Glossy photographs are shiny and smooth. There is more contrast in glossy photos so the images tend to appear sharper and colours more vibrant. Glossy finishes are often used when you want more clarity and for detailed, technical prints. The downside to glossy finishes is that they are very reflective and often have a strong glare. Furthermore, they show fingerprints very easily and often smudge.
Matt finishes are dull and non-reflective. Thus, there is no glare. The paper is texturised with a "pebbled" look. Matt photos don't show fingerprints or smudges. Thus, matt is often used for wallet-size pictures that are frequently handled.
Lustre is in between matt and glossy in both shine and texture. It is moderately textured and has some shine to it. It does not show fingerprints or smudges as easily as glossy. While glossy finishes highlight contrasts making sharper images, lustre subdues them. Thus, they are often best used for softer images.
When to Use
Deciding whether to use a glossy or lustre finish often depends on personal preference. Some people love the glossy look, while others think it does not look professional. However, there are a few general points to note when deciding. If you are going to frame a photo, lustre is often preferred. Glossy photos can stick to the glass, so if you are going to frame a glossy image, it is best to leave space between the photo and glass. If the photo will be placed in sunlight, glossy photos are very reflective and will likely have a glare from various angles. Lustre is also better than glossy for photos what will be handled or passed around.
Portrait and wedding photographers often prefer lustre photos. Lustre is softer and it hides imperfections.