Why marketplace previews lie (and how this checklist works)
Marketplace previews are usually rendered in idealised conditions: stock artwork that suits the file, perfect lighting, hero crop. Real production use looks nothing like that. Brand artwork is the wrong colour, the wrong contrast, has unexpected transparency; the file is opened on a different OS by a different version of Photoshop; the use-case isn’t a hero shot but a 320 px-wide social card.
The seven tests below are what TheLayer’s reviewers run on every mockup file we score. They take ~15 minutes per template, no specialist tooling needed beyond Photoshop or Affinity Photo, and they expose the gap between “renders nicely in the preview” and “works as a production asset.”
The seven tests
1. Smart-object replace-contents fidelity
Open the layered file. Find the smart object that holds your artwork. Right-click → Replace Contents with a high-contrast SVG (try a brand wordmark with a coloured background and a separate transparent variant).
Watch for:
- Does the artwork land at the expected position, size and rotation?
- Does the file save and reopen with the artwork intact?
- Are layer styles and effects applied to the smart object behaving as expected?
A common failure mode: the smart object has a transform on the inner layer that doesn’t reset when contents are replaced, so your artwork ends up half off-canvas.
2. Displacement map honesty
If the mockup pretends to wrap around fabric, paper, ceramic or any non-flat surface, it should use a displacement map — not just a perspective transform.
Drag in a single-pixel-wide white grid as the artwork (a 4 px × 4 px white grid on transparent background works). The grid should follow the surface’s contours. If the lines stay perfectly straight, displacement is fake — the result will look right with thick logos but unconvincing with thin type or fine line art.
3. Shadow and highlight tonal range
Replace the artwork with a mid-grey solid (#808080). Look at where the file applies shadows and highlights. The mid-grey should appear darker in shadowed regions and lighter where the surface catches light — but not become pure black or pure white.
If the file crushes mid-grey to black, your darker brand colours will look muddy. If it blows mid-grey to white, your lighter brand colours will lose detail. Either is a workflow tax you’ll pay every time you use the file.
4. Layer organisation discipline
Open the layers panel. Count how many top-level groups you can identify by name in five seconds. If the answer is fewer than three, the file is going to cost time on every reuse.
Markers of discipline:
- Named groups (not “Group 1”, “Group 12 copy 3”).
- Smart objects clearly labelled with what they hold.
- Helper layers that adjust the look (lighting, shadow, surface) named accordingly and not labelled “Layer 14”.
- Disabled / reference layers either deleted or marked with a
[ref]prefix.
5. Resolution and effective output size
Check the canvas size in Image → Image Size. A “high-res” mockup should be at least 3000 px on the long edge at 300 PPI, comfortably enough for editorial print. Then check whether the smart-object’s inner artwork is also high-res — many mockups have a 4000 px canvas but a 600 px-wide smart object that scales artwork up, smearing detail.
6. Color management
File → Document Color Settings: is there a profile embedded? If not, your colour pipeline is going to drift between the design tool, the mockup file and your final output. For print-bound work, look for files with Adobe RGB (1998) or ProPhoto RGB; for web-only, sRGB IEC61966-2.1 is fine but should be explicit, not “Untagged”.
7. License clarity (the only test that doesn’t involve the file)
Open the marketplace listing or vendor’s licence page. In one sentence each, you should be able to answer:
- Can I use this commercially? (Yes / No / With restrictions)
- Can I use this for print-on-demand products?
- Is there a monthly / annual download cap?
- Does the licence transfer to clients if you’re a freelancer?
- Is the licence per-seat or per-organisation?
If any of those is genuinely unclear after a careful read, the licence is a workflow risk — write to the vendor before you spend, not after.
What this checklist does not do
- It doesn’t tell you whether the file is on-trend visually — that’s a taste decision, not a quality decision. We cover taste in reviews, not here.
- It doesn’t replace client-specific evaluation — your particular use case may stress the file differently. The checklist exposes general production-readiness, not project-specific fit.
- It can’t evaluate third-party scripts or plugins the file might require. Mockup files that need an external displacement engine are usually flagged in the marketplace listing — read carefully.
When to walk away
You don’t need to fail every test to walk away. In our experience reviewing files for the publication, two failures across categories 1–3 (the file behaviour tests) is enough to pass on the file. A failure in category 7 (licence clarity) is a hard stop until the vendor clarifies, regardless of how good the file looks.
The 15 minutes you spend on this checklist saves the 6+ hours of rework that a bad file costs in production.
TheLayer reviewers run this checklist on every mockup template we score. The full scoring rubric lives at /methodology/ — the seven tests above are the qualitative subset; our published reviews score these against a weighted 100-point rubric.