I suggest you get some good canvas, and draw something nice and basic with waterproof paints, like the heptameron circle. It's a 6, 7, 8, and 9 foot ringed circle. The 6 foot inner circle is for tiphareth, the 7 foot circle is for netzach, the 8 foot circle for mercury, and the 9 foot circle on the outside of all those is for yesod. So it's a very powerful circle with lots of kabbalistic symbolism.
Between all of those rings, you fill in the names of god, archangel names with seals, angel names, names of the day and hour, season, etc. depending on the evocation. Basically, the circle is just the rings, and depending on the day and time of the operation, you fill them in with pencil for example with the appropriate names and seals. After you're done, just erase them.
I can help you find some affordable canvas (online) big enough for that if you want (IMG:
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