Will it harm any food you put in there afterwards?
probably the best thing to use is garbage bags but if you have alot of different materials i would use felt, cut holes where you want ur plants and there you go.(color doesnt matter, but green looks better.
Grass and weeds will eventually grow from the carpetCotton fabric will dissolve over timeHeavy layers of newspaper that you get wet will work and eventually decompose will work for a while, this can be covered with a synthetic fabric and may last longer.
I've been mulching beds for 30 years, and have come to the conclusion that there are disadvantages to all of itYou just have to decide what kind of inconvenience you want whereMy favorite method is to lay down at least eight layers of newspaper and cover with a couple inches of hardwood mulchI've used carpet, and have found that it needs to be HEAVY, with a tight backingWeeds will grow through anything that's not super thickIf you want to add plants, cut an X through it to plant, and then lay the carpet back around it Black plastic will semi-decompose into hundreds of small ugly pieces that turn up for yearsSewing fabric will let weeds grow throughThe problem with many weed barriers, such as landscape fabric or carpet, is that weed seeds, brought by the wind or birds, will grow on the top of itThey'll send down roots through the barrier, and be extremely difficult to pull or dig outThat's the most compelling reason I have for using newspaperThose layers will last a long time and do a good job, and it's much easier to work with when you make changesHope this helps.
Your oven won't get hot enough to make the clay particles fuseA kiln is required to fire pottery to at least 1500/1800 degrees FAnd it also must be a slow heat to prevent thermal shock in the clayIf you want to seriously work in clay, look in the yellow pages for a potter or ceramics workshop and get them to supply you with the kind of clay they fireMost will also rent kiln space to youGood Luck!
