How is Monsieur Loisel characterized in "The Necklace"?

Although the
character of Monsieur Loisel is not as developed as his wife, we actually do learn quite a bit
about him through indirect .  He is basically under his wifes thumb, but he is resourceful.  He
responds to her every whim, regardless of what he wants.  He pays the price for her vanity, but
he gets things done.

Monsieur Loisel does seem to be a loving husband.  He
procures a ticked for a fancy ball for his wife because he thinks she would want to go.  He does
seem genuinely surprised by his wifes reaction.

"Why,
my dear, I thought you would be glad. You never go out, and this is such a fine opportunity. I
had great trouble to get it. Every one wants to go; it is very select €¦ (p. 2)

When his wife cries because she does not have enough money to buy a
dress, he gives in.  He gives her the money he had saved for his gun.

He grew a little pale, because he was laying aside just that amount
to buy a gun and treat himself to a little shooting next summer on the plain of Nanterre €¦ (p.
3)

Yet he gives her the money.  When she complains
further that she has no jewels, he gets frustrated, but he has a suggestion for that
too.

"Go look up your friend, Madame Forestier, and
ask her to lend you some jewels. You're intimate enough with her to do that." (p.
3)

When they go to the ball, it is even clearer that he
went for her.  He falls asleep while she is still dancing (he is clearly not the jealous type). 
He swoops in again to save the day when the jewel is lost.  He gives her an excuse to write the
friend to bide them time, and then borrows the money.

That
dreadful debt must be paid. She would pay it. They dismissed their servant; they changed their
lodgings; they rented a garret under the roof.  (p. 6)

Although she only sees her own suffering, he suffers right there with her.  Everything
she gives up, he gives up too.  He moves when she moves.  He takes on extra work.  For ten years
he labors with her until the debt is paid.

Although the story does seem to
focus more on Mathilde, we do learn quite a lot about her husband.  He is intelligent, humble,
and hard-working.  He puts up with quite a lot from his vain wife, and he sticks by her.  He
will do whatever she wants.