You probably get told to sit up straight when you're at school, but it's not just to make the room look tidier.
Doctors say that slouching at your desk when you're young could damage your back when you get older.
So what's the furniture like at your school?
Have you got brand new stuff that's really comfy, or dead old desks and chairs covered in graffiti and chewing gum?
Maybe your equipment is getting on a bit, but is still really nice to sit at?
Whatever your furniture is like, we want to know about it.
Unfortunately this topic is now closed but there are Comments pages on other subjects on the main Chat index.
"There is glue and gum under the tables and the chairs are hard and they hurt your back. YUCK!"
Georgia, 8, London, England
"We have chewing gum and graffiti under the chairs and tables. We have hard, plastic chairs and tables which are too small for our folders. I'm SO looking forward to secondary school!"
Sepha, 11, London, England
"Our school chairs hurt sooo much. I'd rather my chairs be made out of fabric instead of hard plastic."
DD, 8, London, England
"I am a boarder at my school and our beds are SO lumpy! We are all hoping for new ones soon."
Poppy, 13, London, England
"The furniture in our school's new building is very good, although the chairs are a bit hard. The old building still has lots of very ugly furniture: old tables full of graffiti and chewing gum and very uncomfortable chairs. I'm glad next year the construction will be over and we'll move into the new facilities. Too bad our Head Teacher didn't know about those modern stools and tables shown on Newsround. I'd love to try them out!!!"
Henrique, 14, London, England
"Well... Our desks are all drawn over, the bottom of every desk in the school is covered in gum and there are no comfortable chairs - apart from the ones in the library!"
Amy, 12, Bournemouth, England
"Our chairs and desks are nothing special but they don't give us backaches. Maybe you should buy your furniture from the USA."
Sarah, 11, Pennsylvania, USA
"Not really, as the chairs are broken on the bottom in some classes. In other classes the tables are too low so you have to lean really low."
Ashleigh, 11, Ipswich, England
"Our chairs are a weird shape - they sort of curve backwards at the top so you can't lean back without falling over! I think we should get new furniture, and the desks are COVERED in chewing gum!"
Rebecca, 14, Kent, England
"My school furniture isn't great. We have plastic chairs with holes at the back and the desks are quite high for me."
Sarah, 11, Oxfordshire, England
"Our school chairs hurt your spine."
Deavion, 8, London, England
"My school's furniture is horrible because my friends are always falling on the floor."
Nirujan, 8, London, England
"Our school chairs are small and children swing on them as well."
Grace, 8, London, England
"In my school, the furniture isn't great, but the chairs are ok if you lean back with one arm over the back. The stools in science and art are very uncomfortable as they have no back and they make your bottom go numb in fifteen minutes. It is very annoying and painful but the desks are worse as they are too low - so if I try to write it hurts my back."
Natalie, 12, Essex, England
"Our tables are really low down. The chairs are wooden and with bars at each side which dig into your legs. They also have a massive hole at the back which really makes your back hurt! I HATE THEM!!
Laura, 12, Ireland
"Our chairs are OK. They are not that bad but they do hurt your back if you sit down on them for too long."
Luke, 8, Essex, England
"My chairs have got writing on them and they are not very comfortable."
Hinna, 12, Woking, England
"Our school has really bad chairs and desks, everyday I go home with back ache. It gets really awkward when you have to share a desk with a friend and you can't have your own space. I wish my school had these new furniture, then I wouldn't have such a bad back."
Amy, 11, London, England
"My school has just got new comfy padded chairs. They are much better than the plastic chairs."
Fariha, 13, Hertfordshire, England
"Some of our chairs are broken and they are not very nice to sit on."
Emma, 12, Oxfordshire, England
"When I finish school I have a bad pain in my back."
Charlotte, 12, Kent, England
"Underneath our school desks there is loads of chewing gum - it's disgusting!!"
Louise, 10, Wokingham, England
"Ours are ok because we are in year 6 we have higher chairs than the rest of the school. They are quite hard but it's better that the lower classes!"
Felicia, 10, Cheshire, England
"My school furniture is ok but sometimes it can hurt your back. I think that every school in the UK should have portable desks."
Kayleigh-Ann, 11, Herefordshire, England
"Our chairs are so uncomfortable - they're horrible plastic ones!"
Rebecca, 11, Scotland
"Our furniture is horrible, the tables and chairs are covered in chewing gum and graffiti. I think the new comfy ones look much better!"
Jasmine, 13, UK
"My school doesn't have good furniture. In fact it's really rubbish! We have hard chairs and normal flat desks. The tables are organized in groups. And they're new! I usually get back pains because of this."
Nahida, 11, London, England
"Our school's furniture is just simple - single tables and chairs. They are very uncomfortable!"
Teddy, 14, Surrey, England
"Our school chairs are too small. When I lean over my back starts to hurt."
Demi, 7, London, England
"Sometimes our knees touch the underneath of the tables and some of the chairs are uncomfortable."
Year 6 class, 10 & 11, Spalding, England
"Our furniture is quite good, but the chairs are made of plastic, which is quite hard. Backache in my family is genetic and the school chairs don't help."
Lauren, 11, Nottingham, England
"On our chairs you fall off because the legs are loose!"
Sam, 12, Devon, England
"There is loads of chewing gum under my school's tables and it's really disgusting."
Ellie, 12, Hampshire, England
"Ours are boring!! It's all wooden and brown and it really needs some decorating."
Skye, 11, Derbyshire, England
"Ours are horrible. Whenever you try to pull the table towards you, you touch gum. Yuck!!"
Alex, 12, London, England
"Our chairs are fairly comfy but you can't write because the desks are too hard."
Emily, 10, Hertfordshire, England
"Our school furniture is quite good but the chairs are not very comfy."
Alice, 10, Somerset, England
"Our chairs are blue plastic but they are still comfy."
Harrison, 10, Manchester, England
"Our chairs are really NOT comfy and the tables look like they are new but they were made in 2001. So my school's furniture is not comfy!"
Kieran, 8, Dundee, Scotland
"In some rooms, the chairs are alright but some are so uncomfortable it is unbelievable. They are thin plastic and after 20 minutes of sitting on them my back is aching."
Ben, 14, Norwich, England
"Our chairs are big and it keeps us comfortable and the desks are the right height for us."
Jessica, 10, Cheshire, England
"There are many people in my school who chew gum, and when they are finished with their gum they either put it under the chair or table, gross!"
Albin, 12, Geneva, Switzerland
"Our school furniture is really uncomfortable and due to one of Newsround's reports I said this in my own youth parliament election manifesto!"
Molly, 11, Wakefield, England
"I hate my chairs in school, they plastic and hard and they break so easily. It really hurts if you're doing an exam for one and a half hours. I can't figure out why people put chewing gum under the table and chairs."
Layla, 13, Hampshire, England
"Our school got new furniture two years ago. The tables are really good because we sit in tables with four other people, not just a desk to ourselves. They are really comfy!"
Johanna, 12, Switzerland