We noticed that 3DWarehouse models with dimensions or text have created large, ugly text for small thumbnails (the thumbnails of your model that are returned in a search or in a collection). We traced this down to an update in SketchUp 2017 that affected our RenderBots (the way we auto-generate other SketchUp versions & thumbnails for your uploaded models). I used 2 users who’s models had text, were recently uploaded, and had dimensions that made their thumbnails look bad: B-Lock Profiles and SIRISAK.
Here’s a picture of the before and after I re-rendered them:
If you have models that have ugly text in them, you can re-upload your models or post a url here and we can help if there are many.