Hi eduard,

thanks for your anwer. Unfortunately that does not work. Size does not change. I am using Expyriment backend.

I solved it this way:

enter = keyboard(keylist = ['RETURN'])
var.Resp_Perc_F= 20
var.Resp_MT = 5000

FB = Canvas()
FB.text('falsche Tastendrücke:  ' , font_size=24, x=-150, y= -50)
FB.text( str(var.Resp_Perc_F)  + ' %', font_size=24, x=70, y= -50)
FB.text('Zeit:   ', font_size=24, x=-50, y=  50)
FB.text(format(var.Resp_MT/float(1000),'.2f') + ' sec' , font_size=24, x=70, y=  50)
if var.Resp_Perc_F > 0 :
	FB.text('   ?', font_size=90, x=150, y= -70, color="red")
if var.Resp_Perc_F == 0 :
	FB.text('   ?', font_size=90, x=150, y= -70, color="green")
FB.show()
clock.sleep(995) #no response fixed timeout #30 sec break = 29995
FB.text('weiter mit Entertaste' , font_size=18, x=250, y= 150)	
FB.show()
enter.flush()	
key, time = enter.get_key()

Cheers
Stephan