advanced

If deselected, slim will not preload any images into browser-cache beforehand. When having slow network speeds and/or large images, this might cause the user to see an empty border (if selected) before the first image is loaded.

If kept selected you can enter the (maximum) amount of images that are preloaded into cache. Preloading is indicated at start by the spinning, red symbol.

If deselected, slim will not load any images into cache after initial preloading. At default (selected), images that are not yet loaded into cache (by initial preloading) will be loaded after selecting the corresponding gallery. Therefore there will be no delay when clicking it's thumbnail in the previewer. Dynamic preloading is indicated by the spinning square on the thumbnails - once gone, it's main image is loaded into cache.

NOT RECOMMENDED: If deselected, thumbnails will not be loaded into cache at all. This causes them to be loaded at runtime, filling the previewer in a sporadic order. In large galleries with many images (and therefore a long thumbnail previewer) thumbnails might be loaded on the far end of the previewer, therefore the user might not see any thumbnails for a certain period of time. This depends on the browser and of course on the networks speeds.