Very thin indeed! That's why I have problems with kneeling in front of a statue, lighting candles and praying. I used to do all these things growing up Catholic in Spain. I don't do it any longer.
Some here are arguing that veneration has nothing to do with "trust is to be reposed in images" to use the RCC's words.
Have you ever put an image of St. Christopher in your car, to keep you safe? My parents would not start the car without such an image.
Have you ever knelt in front of a statue of St. Anthony to ask for help finding something important you misplaced? A few years ago I was teaching at a Catholic HS here, in the US, when the chemistry tests the students had taken earlier that day misteriously "disappeared" from my desk. The headmistress wanted me to go to the chapel and pray in front of a statue of St. Anthony, asking him for help finding the papers.
Growing up in Spain I went to quite a few villages when they were taking the statue of the patron saint in procession, asking him or her to send rain. A few times they were asking for intercession, most times they were asking for the saint to provide the rain.
I could keep on going, but you get the idea!
Any real Catholic knows we ask for Prayerss from the saints. I have asked Prayers from Saint Benedict with Christ. Instaneous healings. In Christ through him in Him and the unity of the Holy Spirit we are asking prayer from the Heavenly Host with Jesus.
When we see chickens sacrificed then I will believe you.