Ballot print becoming too small to read

Not only have tablecloth-sized Senate ballot papers become unwieldy, it's getting to the point where some voters may not even be able to read them.

Australian Electoral Commission chief Tom Rogers says for the 2013 election 300,000 plastic magnifying sheets had to be purchased because the font size on ballot papers had to be shrunk to just 7.65 in some states.

With a record number of candidates expected to step forward at the next federal election the situation could become worse.

"I have to tell you ... I'm struggling to see 7.65," the bespectacled Mr Rogers told a Senate estimates hearing in Canberra on Tuesday.

If there was a further increase in the number of candidates, "at what point does that actually become illegible".