When editing a surface material it is important that the acceptable sanitizers and acceptable cleaners for this surface material have already been created.
Please reference these documents this document on creating sanitizers and this document on creating cleaners if you have not already done so.
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Now, select the acceptable sanitizers and acceptable cleaners. You may also upload an image by clicking on “Drop files here or Browse” and selecting it from the file explorer that appears. You may also drag and drop an image from your desktop or file explorer.
Once finished, click “Save”.