Rijksmuseum lets you download high-resolution art images for free

The detail is the useful bit

Rijksmuseum is not just The Night Watch. The useful part for designers is the amount of high-resolution detail: ceramics, textiles, frames, flowers, maps, ships, ornament and colour combinations that do not feel computer-generated.

The museum says images of most artworks can be downloaded free from the artwork page, with JPEGs averaging around 4500 by 4500 pixels. That is big enough to actually inspect details.

What to look for

Search boring words first: tile, border, flower, chair, map, plate, textile, ship, frame. Famous names are fine, but the side objects often give better product ideas.

Delft-style blues, frame corners, old labels and small painted objects can inspire patterns, packaging, engraving ideas and colour palettes.

I would screenshot nothing as the final source. Download from the work page, then crop or trace your own study from the proper high-resolution file.

Use it properly

Do not assume every item has the same rights. Open the work page, check the note, and avoid implying museum endorsement.

Also remember that the useful bit might only be a crop or tiny detail. A corner of a tile can be more valuable than the entire painting if you are making a pattern.

My take: this is one of the better archives when you need old-world polish without making something feel like fake antique clipart. Zoom in. The small details are where the good stuff is.