The laser doesn't print, and it doesn't lay ink on the cover. It changes the colour of the leather it touches, and how much it changes depends on the colour you start with. That one fact decides more about how your finished notebook will look than anything else on this site, so it's worth explaining before the parcel arrives.
What the beam actually does to the leather
Every design here is engraved onto a vegan PU leather cover, in-house, in the UK. The beam doesn't cut through the surface or add anything to it. It heats the leather just enough to change its colour.
On some covers the engraving comes out darker than the leather around it, on others lighter, and on a few it's almost black. Each colour has its own result, which is why we test every one.
Why your cover colour changes how much wording you'll see
All the contrast comes from the difference between the leather and the mark. Where that difference is big, the engraving reads clearly across a room. Where it's small, the mark is physically there, but at a glance it can all but disappear.
Neither one is better made. It's the same engraving either way, and the only thing that changes is how loudly it announces itself.
Which colour to pick, and for what
The choice is really about how much you want the engraving to carry the object.
If the wording is the point (a name, a date, a definition, a line you want read across a desk), pick a cover where the preview shows strong contrast.
If you'd like the engraving to be a private detail, pick one where it's subtle. There, a monogram reads as texture until someone tilts it to the light and finds it. Some people want precisely that, and it's a lovely thing when they do. Just don't choose it for a long message you're hoping will be legible at arm's length.
Photographs need more contrast than anything else here. A portrait is built from fine tonal detail, where lettering has a few bold strokes, so it has the most to lose on a low-contrast cover.
You don't have to take any of this on faith
Every product page draws your actual wording onto the cover colour you've chosen before you pay, in that colour's own engraving tone, emulating the contrast you'll see on the real book. If a colour is going to swallow your message, you'll see it while you're still choosing, long before the parcel lands.
The colours on screen are a close match rather than an exact one.