Painters w/o Insurance

[Michael Gloss]

First time poster, long time researcher/reader.  I just had a GC repair all the rotten wood on our exterior trim and now need to hire a painter to scrape and paint the exterior trim.  42 windows, so big job.  We own and occupy this duplex (buy and hold, not flip).  Homeowners insurance plus $1m umbrella policy.  A painter I received a quote for said she didn't have any insurance (liability or workmans comp).  The painter would use a helper, so two people working the job.  

Do I need to only look at painters with insurance and what type/amounts?  Finally, should i ask for a copy of proof of insurance?